Daniel Algom

• Tel Aviv University

In 1948, Claude Shannon published a revolutionary paper on communication and information in engineering, one that made its way into the psychology of perception and changed it for good. However, the path to truly successful applications to psychology has been slow and bumpy. In this article, we present a readable account of that path, explaining th...

Much research in food psychology has examined the influence of perceptual features – color, texture, packaging – on preference for that food. Here, we addressed the reverse question of the influence of food preference on the perception of its quantity. Does a portion of a loved food appear different than the same portion of a hated food? We probed...

Older adults process emotional speech differently than young adults, relying less on prosody (tone) relative to semantics (words). This study aimed to elucidate the mechanisms underlying these age-related differences via an emotional speech-in-noise test. A sample of 51 young and 47 older adults rated spoken sentences with emotional content on both...

Recent global events have called for the development of online testing and evaluation techniques, for both clinical and research purposes. Online testing is especially important for older adults who might have limited access to health services due to mobility difficulties or health risks. The current study aimed to validate an online tool, Internet...

Older adults process emotions in speech differently than do young adults. However, it is unclear whether these age-related changes impact all speech channels to the same extent, and whether they originate from a sensory or a cognitive source. The current study adopted a psychophysical approach to directly compare young and older adults’ sensory thr...

The popular measure of Garner Interference specifies the detriment to performance with the task-relevant attribute in the presence of a randomly varying distractor. But is irrelevant variation per se responsible for this breakdown of selective attention as the traditional account suggests? In this study we identified an overlooked alternative accou...

The Stroop effect has been a key to the assay of selective attention since the time of the epoch-making study by J.R. Stroop almost a century ago. However, recent work based on computational modeling and recording of brain activations ignored the primary meaning of the Stroop effect as a measure of selectivity—with the Stroop test losing its raison...

The term “Weber–Fechner law” is arguably the most widely used misnomer in psychological science. The unification reflects a failure to appreciate the logical independence and disparate implications of Weber’s law and Fechner’s law as well as some closely aligned ones. The present statement, long overdue, is meant to rectify this situation. I discus...

We report a new discovery on the role of hands in guiding attention, using the classic Stroop effect as our assay. We show that the Stroop effect diminishes, hence selective attention improves, when observers hold their chin, emulating Rodin's famous sculpture, “The Thinker.” In two experiments we show that the Rodin posture improves the selectivit...

As a vital part of our daily lives, number processing has received much attention in current cognitive research. Most adults perceive with ease the numerical magnitude of a two-digit number and also the individual magnitudes of the component digits, yet the relation between the 2 is poorly understood. Application to two-digit numbers of Garner's sp...

Music generates manifold experiences in humans, some perceptual and some hedonic. Are these qualia governed by the same principles in processing? In particular, do the loudness and timbre of melodies combine to produce perception and likeability by the same rules of integration? In Experiment 1, we tested selective attention to loudness and timbre...

According to a growing consensus, the Stroop effect is understood as a phenomenon of conflict and cognitive control. A tidal wave of recent research alleges that incongruent Stroop stimuli generate conflict, which is then managed and resolved by top-down cognitive control. We argue otherwise: control studies fail to account for major Stroop results...

In the number-to-position methodology, a number is presented on each trial and the observer places it on a straight line in a position that corresponds to its felt subjective magnitude. In the novel modification introduced in this study, the two-numbers-to-two-positions method, a pair of numbers rather than a single number is presented on each tria...

we test the hypothesis that naming an object depicted in a picture, and reading aloud an object’s name, are affected by the object’s speed. We contend that the mental representations of everyday objects and situations include their speed, and that the latter influences behavior in instantaneous and systematic ways. An important corollary is that hi...

Judgments of the physical size in which a numeral is presented are often affected by the task-irrelevant attribute of its numerical magnitude, the Size Congruity Effect (SCE). The SCE is typically interpreted as a marker of the automatic activation of numerical magnitude. However, a growing literature shows that the SCE is not robust, a possible in...

In early studies employing the SFT, the stimuli were simple visual signals, mainly dots, lines, or letters of the alphabet. Although this feature facilitated focusing on theory development, it has reduced the impact of SFT on mainstream cognitive science. The goal of this chapter is to reconnect the SFT to cognitive psychology via an SFT-guided exa...

Stroop objects are defined by the existence of a logical relationship, congruity or incongruity, between their constituent dimensions. The Stroop effect is the difference in performance between congruent and incongruent stimuli with respect to one of these dimensions. However, the pair of Stroop generating dimensions does not exhaust all dimensions...

We have recently reported the discovery that the ability to detect a minimum increment to a stimulus depends on the spread of the other stimuli for which this just noticeable difference (JND) is being measured (Namdar, Ganel, & Algom, 2016). In particular, the JND around a standard stimulus was larger when the other standards tested within the same...

Research in the allied domains of selective attention and perceptual independence has made great advances over the past 5 decades ensuing from the foundational ideas and research conceived by Wendell R. Garner. In particular, Garner’s speeded classification paradigm has received considerable attention in psychology. The paradigm is widely used to i...

The emotional Stroop effect (ESE) is the result of longer naming latencies to ink colors of emotion words than to ink colors of neutral words. The difference shows that people are affected by the emotional content conveyed by the carrier words even though they are irrelevant to the color-naming task at hand. The ESE has been widely deployed with pa...

The authors report the discovery of a new effect of context that modulates human resolving power with respect to an individual stimulus. They show that the size of the difference threshold or the just noticeable difference around a standard stimulus depends on the range of the other standards tested simultaneously for resolution within the same exp...

We report the discovery of a new effect of context that modulates the human resolving power for an individual stimulus. In particular, we show that the size of the difference threshold or the just noticeable difference around a standard stimulus depends on the range of the other standards tested simultaneously for resolution within the same experim...

We test the hypothesis that naming an object depicted in a picture and reading aloud an object's name are affected by the object's speed. We contend that the mental representations of everyday objects and situations include their speed, and that the latter influences behavior in instantaneous and systematic ways. An important corollary is that high...

The production effect is the difference in memory favoring words read aloud relative to words read silently during study. According to a currently popular explanation, the distinctiveness of aloud words relative to silent words at the time of encoding underlies the better memory for the former. This distinctiveness is attributable to the additional...

The presence of the Stroop effect betrays the fact that the carrier words were read in the face of instructions to ignore them and to respond to the target ink colors. In this study, we probed the nature of this involuntary reading by comparing color performance with that in a new forced-reading Stroop task in which responding is strictly contingen...

In an attempt to measure how mode of response might affect psychophysical judgment, 18 subjects were asked to give magnitude estimates of the loudness of 1000-Hz tones at various sound pressure levels in each of two sessions. In one session, the subjects responded by giving their numerical judgments orally to the experimenter; in the other session,...

Drawing from construal level theory, we test the hypothesis that words promote thinking of events in terms of their abstract and central features (i.e., high-level construal), whereas pictures promote thinking in terms of more concrete and idiosyncratic features (i.e., low-level construal). In Experiments 1a and 1b, we found that verbal (vs. pictor...

The vast majority of studies performed on the priming of attitudes, dispositions, and behavior en-gaged non-selective group of students as participants. This study engaged highly skilled experts as well as student cohorts. In a series of 3 experiments, professional chess players as well as non-se-lected groups of students were primed for risk-takin...

Previous research has shown that the fingers' aperture during grasp is affected by the numerical values of numbers embedded in the grasped objects: Numerically larger digits lead to larger grip apertures than do numerically smaller digits during the initial stages of the grasp. The relationship between numerical magnitude and visuomotor control has...

The aim of the study was to explore whether temporal information processing can interfere with performance of a non-temporal task. A new methodology based on the Garner paradigm was employed. Participants were asked to classify two-dimensional stimuli according to either length or duration, with and without variation in the other (task-irrelevant)...

Sustained effects of emotion are well known in everyday experience. Surprisingly, such effects are seldom recorded in laboratory studies of the emotional Stroop task, in which participants name the color of emotion and neutral words. Color performance is more sluggish with emotion words than with neutral words, the emotional Stroop effect (ESE). Th...

When words at study are divided into to-be-remembered and to-be-forgotten ones, people recall more of the former than of the latter in a surprise memory test for all words. In this study, we also tapped memory for word identity at study (forget or remember) by asking participants to reproduce in memory selected portions of the original words. We fo...

It takes people longer to name the ink colour of emotion or threat words than that of neutral words, the emotional Stroop effect (ESE). In three experiments with normal and patient populations, we show that the ESE is a special case of a generic attention model and effect entailed in Garner's speeded classification paradigm. Guided by the Garner mo...

In the emotional Stroop effect (ESE), people are slower to name the ink color of negative, emotion-laden words than that of neutral words. Two accounts have been suggested for the ESE, relating it to either de-ficient attention to color or to temporary disruption of action in the face of threat. Is the ESE driven by a threat-produced change in perc...

Human resolution for object size is typically determined by psychophysical methods that are based on conscious perception. In contrast, grasping of the same objects might be less conscious. It is suggested that grasping is mediated by mechanisms other than those mediating conscious perception. In this study, we compared the visual resolution for ob...

To test the generality of our results, a standard trial-by-trial normalization procedure was applied for the movement data of Experiment 1.Each data point in each trial was normalized by the initial opening between the fingers in this trial (from which the size of the start button was subtracted). As can be seen in the figure, the new analysis yiel...

Human resolution power in the various senses is experimentally determined by a range of known psychophysical methods. A trivial yet critically important feature of classical psychophysics is that its methods are based on conscious perception. In contrast, grasping of the same stimuli might be less conscious. Recent findings from our laboratory show...

In order to gauge in a precise fashion the capture of attention by emotional stimuli, we developed a new tool that imports the classic Stroop effect into the realm of emotion. Strooping the typical emotion tasks enabled the derivation of a pure intraitem measure of attention under emotion. The results of two experiments showed that the classic Stro...

In the laboratory, people classify the color of emotion-laden words slower than they do that of neutral words, the emotional Stroop effect. Outside the laboratory, people react to features of emotion-laden stimuli or threatening stimuli faster than they do to those of neutral stimuli. A possible resolution to the conundrum implicates the counternat...

According to Weber's law, a fundamental principle of perception, sensitivity to changes in magnitude along a given physical dimension decreases when stimulus magnitude increases. In other words, the increment needed in order to detect a change - the Just Noticeable Difference (JND) - is smaller for weak stimuli compared to stronger stimuli. Althoug...

The tactile communication between the symbiotic goby Cryptocentrus steinitzi and its burrowing shrimp partner Alpheus purpurilenticularis was investigated by film analysis. Warning signals of the goby which elicit the retreat of the shrimp into its burrow consist mainly of rapid fin flicks transmitted to the shrimp through its long antennae. Five d...

An experimental analysis of predator face recognition was carried out using 360 Chromis caeruleus. Members of this species discriminated between a multicued, two-dimensional model of a piscivorous fish (Fam. Serranidae) and a typical non-piscivorous fish (Fam. Acanthuridae). Mouth size and shape were important discriminatory cues. The disruptive pa...

A morphometric analysis of 20 different facial features of reef fishes was carried out in order to assess cues which could serve for predator recognition. 105 different species of 35 different families were included in this study. The main features of potential discriminatory value were head width, head shape, the size of the mouth and its shape, t...

The emotional Stroop effect demonstrates that people are slower to name the ink colour of emotionally charged words than that of neutral words. Attributing this slowdown to emotionality or threat requires that the emotion and neutral words presented are equal on all extraneous variables. However, it is impossible in principle to match the two types...

Do various operational definitions of visual attention tap the same underlying process? To address this question, we probed visual selective attention using orientation of attention, flanker, and Stroop tasks. These were embedded in combined designs that enabled assessment of each effect, as well as their interaction. For the orientation task, perf...

A huge set of focused attention experiments show that when presented with color words printed in color, observers report the ink color faster if the carrier word is the name of the color rather than the name of an alternative color, the Stroop effect. There is also a large number (although not so numerous as the Stroop task) of so-called "redundant...

The type of processing of numerical dimensions varies greatly and is governed by context. Considering this flexibility in tandem with a fuzzy demarcation line between automatic and intentional processes, it is suggested that testing the effect of notation should not be confined to automatic processing, in particular to passive viewing. Recent behav...

Purpose To clarify the relationship between psychoacoustic capabilities and speech perception in adolescents with severe-to-profound hearing loss (SPHL). Method Twenty-four adolescents with SPHL and young adults with normal hearing were assessed with psychoacoustic and speech perception tests. The psychoacoustic tests included gap detection (GD),...

We report a series of investigations into the effects of common names, physical identity, and physical similarity on visual detection time. The effect of these factors on the capacity of the system processing the signals was also examined. We used a redundant targets design with separate testing of the target-distractor (single target), target-targ...

A series of 8 experiments investigated the association between pictorial and verbal representations and the psychological distance of the referent objects from the observer. The results showed that people better process pictures that represent proximal objects and words that represent distal objects than pictures that represent distal objects and w...

A cornerstone of contemporary research in numerical cognition is the surprising link found between numbers and space. In particular, people react faster and more accurately to small numbers with a left-hand key and to large numbers with a right-hand key. Because this contingency is found in a variety of tasks, it has been taken to support the autom...

People indicate the physical size or the parity status of small numbers faster by a left-hand key and those of larger numbers by a right-hand key. Because magnitude information is not required for successful performance in these tasks, the presence of a number-space association (the SNARC effect) has been taken to indicate the automatic activation...

In a recent study [1], we found that Weber's law, a fundamental principle of perception, does not govern visual control of grasping and concluded that different representations of object size are used for action and for perception [1]. Smeets and Brenner [2] suggest instead that grasping is computed on the basis of position rather than on the basis...

According to Weber's law, a basic perceptual principle of psychological science, sensitivity to changes along a given physical dimension decreases when stimulus intensity increases [1 • Marks L.E. • Algom D. Psychophysical scaling.in: Birnbaum M.H. Measurement, Judgment and Decision Making. Academic Press, San Diego, CA1998: 81-178 • Crossref • G...

We investigated the perception of emotional stimuli in anxious individuals and nonanxious cohorts. Signal detection theory analysis was applied to the discrimination of emotionally charged faces at several points along a continuum of emotional intensity. This design permitted the derivation of multiple measures of sensitivity and response bias for...

A picture-word version of the Stroop task was used to test the automatic activation of psychological distance by words carrying various senses of psychological distance: temporal (tomorrow, in a year), social (friend, enemy), and hypotheticality (sure, maybe). The pictures implied depth, with the words appearing relatively close to or distant from...

The size congruity effect is the interesting result that comparisons of the sizes of the physical formats in which numerals appear are affected by the numerical magnitudes of the respective numerals. We demonstrated that separating the physical and the numerical attributes in space leaves the effect unchanged. We then applied the spatially separate...

Psychophysics is the scientific study of the relation between stimulus and sensation, and therefore its study concerns fundamental questions of psychology and cognitive science.

The Stroop effect is psychology's classic measure gauging the selectivity of attention to individual attributes of complex stimuli. The emotional Stroop effect gauges the influence on behavior of threat and emotional stimuli. The former taps central/executive processes abstracted from particular stimulus contexts, whereas the latter taps automatic...

The Emotional Stroop Effect (ESE) was tested for accuracy. A severe time limit imposed on reporting produced relatively high rate of errors, documenting the ESE for the first time for accuracy (higher error rates in naming the color of emotional words), and enabling the application of the Theory of Signal Detectability. The results showed that the...

The role of Stroop processes in the emotional Stroop effect was subjected to a conceptual scrutiny augmented by a series of experiments entailing reading or lexical decision as well as color naming. The analysis showed that the Stroop effect is not defined in the emotional Stroop task. The experiments showed that reading, lexical decision, and colo...

Three influential perspectives of social cognition entail conflicting predictions regarding the selectivity of performance under stress. According to the attention view, selectivity to the task-relevant attribute improves under stress because of reduced utilization of task-irrelevant attributes. According to the capacity-resource approach, stress d...

The goal of avoiding distraction (e.g., ignoring words when naming their print colors in a Stroop task) is opposed intrinsically by the penchant to process conspicuous and correlated characteristics of the environment (e.g., noticing trial-to-trial associations between the colors and the words). To reconcile these opposing forces, the authors propo...

It is commonly believed that humans are unable to ignore the meanings of numerical symbols, even when these meanings are irrelevant to the task at hand. In 5 experiments, the authors tested the notion of automatic activation of numerical magnitude by asking participants to compare, while timed, pairs of numerical arrays on either numerosity or nume...

Pictures of animals with names of animals printed within the pictures were presented for comparative judgments of size based on either the pictures or the names. The picture-word compounds were compared faster with picture than with word as the relevant dimension. The comparisons of pictures were free of interference from the irrelevant names, but...

Participants named (Experiments 1-2) or categorized (Experiments 3-4) the picture or the word of picture-word compounds that varied in the relative saliency of the 2 components and in the correlation between them over the experimental trials. Picture-word interference (PWI) was gauged through Stroop and Garner effects. PWI was found to be malleable...

Participants named (Experiments 1–2) or categorized (Experiments 3–4) the picture or the word of picture–word compounds that varied in the relative saliency of the 2 components and in the correlation between them over the experimental trials. Picture–word interference (PWI) was gauged through Stroop and Garner effects. PWI was found to be malleable...

Presented with Stroop color-word stimuli, participants were asked to make one response ("Yes") to the appearance of the word RED, the color red, or both and another response ("No") when none of these targets (defined by redness) appeared. The same participants also performed in the standard Stroop task, naming the print color of the same set of col...

The focus of research in memory psychophysics has moved from a preoccupation with magnitude scaling to studying response times and information processing. The need for integrating these research traditions is stressed.

In 6 experiments probing selective attention through Stroop classification, 4 factors of context were manipulated: (a) psychophysical context, the distinctiveness of values along the color and word dimensions; (b) set size context, the number of stimulus values tested; (c) production context, the mode used to respond; and (d) covariate context, the...

Five experiments demonstrate that context has a powerful effect on the ease with which people can name (Experiments 1-3) or categorize (Experiments 4-5) a stimulus while ignoring another stimulus, irrelevant or conflicting with the target. Selectivity of attention to the target dimension was gauged through Stroop and Garner effects. When the stimul...

A Detection-by-Compression Theory is developed and shown to account for behavioral detection times subsumed in the literature under the rubric of "visual search." According to the theory, exposure to visual stimuli invariably results in the instantaneous compression of the input by means of an algorithm mimicking Principal Component Analysis. The a...

Space- or object-based models, on the one hand, and structural-informational models, on the other hand, reflect conceptually distinct approaches to visual selective attention. In 3 studies, the authors contrasted these approaches by jointly applying prototypical routines prescribed in each approach. Following a space-based paradigm developed by M....

Space- or object-based models, on the one hand, and structural–informational models, on the other hand, reflect conceptually distinct approaches to visual selective attention. In 3 studies, the authors contrasted these approaches by jointly applying prototypical routines prescribed in each approach. Following a space-based paradigm developed by M....

In 7 experiments, participants selected the larger member of pairs of digits that differed in numerical magnitude as well as in physical size. Selective attention to the relevant dimension (number or size) was gauged by Garner and Stroop interference, both of which varied considerably as a function of the number and relative discriminability of val...

Reviews issues and criticisms that marked the first program to measure sensations. Perspectives are provided to evaluate the virtues and vulnerabilities of the scaling methods and theories, both classical and modern. The main body of the chapter reviews a wide array of relevant data and theories. The 2 notions of sensory distance and sensory magnit...

Symmetry is usually viewed as a discrete feature: an object is either symmetric or non-symmetric. In this presentation, symmetry is treated as a continuous feature and a continuous measure of symmetry (the Symmetry Distance) is defined. This measure can be easily evaluated for any shape or pattern in any dimension. A preliminary study presented her...

D. Algom and W. S. Cain (1991b) found relative invariance in the pattern of judgments of perceptual and mental mixtures of banana and grass odors. Invariance held both for judgments of total intensity and for those of an individual constituent. For 2 tastes, H. N. J. Schifferstein (1997) found a pattern with both similarities to and differences fro...

The current paper examines the question of why Freud employed Greek rather than Hebrew foundation legends, specifically the story of Oedipus, as a basis for psychoanalysis, Freud's choice of Oedipus emanates from his deterministic view of the universe, paralleling the Greek rather that the Biblical story of creation. In the Biblical account God pre...

The literature on numerical perception is reviewed from the standpoint of research on selective attention, and predictions are made concerning the dimensional interaction between physical and numerical size of numerals. We manipulated stimulus differences to make the classification of numerical value slightly better (Experiment 1), substantially be...

The distinction that Koriat & Goldsmith have drawn between laboratory and naturalistic research is largely valid, but the metaphor they have chosen to characterize the latter may not be optimal. The “correspondence” approach is vulnerable on conceptual grounds and is not applicable to significant portions of empirical research.

Pair formation was studied in a polymorphic population of Gambusia holbrooki in a brackish drainage canal in Southern Florida. All females and the majority of males were gray colored and only 5% of the males were black spotted. A small fraction of the population formed pairs, composed of a female and a male that swam synchronously and close togethe...

The ability to lateralize and discriminate dichotic clicks was tested in multiple sclerosis patients with normal audiograms and in normal cohorts. Lateral position spread over a greater range with interaural level differences than with interaural time differences, and was related to the two asymmetries by different functions. Measures of binaural a...

The ability to lateralize dichotic clicks with either interaural time delays (ITD) or interaural level differences (ILD) was tested in seven multiple sclerosis (MS) subjects who had normal audiograms. Along with the psychoacoustical tests, magnetic resonance images (MRI) of the subjects' brainstem were obtained. After matching each MRI section with...

Subjects (42 girls 17 or 18 years old) overlearned to different criteria the associations between circles and the symbolic codes that stood for the circles when their areas were assessed from memory. Consistent with the prediction from the uncertainty theory but conflicting with the prediction from the reperception hypothesis, familiarity with the...

Separate groups of women estimated the painfulness of labor contractions either immediately (perceptual judgments) or at time intervals varying from 8 to 48 h after their completion (memorial judgments). The pain judgments of individual uterine contractions were related functionally to the biometrically measured magnitude of these contractions. Per...

Symmetry is usually viewed as a discrete feature: an object is either symmetric or non-symmetric. In this presentation, symmetry is treated as a continuous feature and a continuous measure of symmetry (the Symmetry Distance) is defined. This measure can be easily evaluated for any shape or pattern in any dimension. A preliminary study presented her...

Subjects made quantitative judgements of the overall intensity of odor-taste mixtures, which were either presented physically (perceptual estimation) or represented symbolically by pairs of colors that referred to their unmixed constituents (memory-based estimation). In the latter condition, the mixtures were constructed subjectively by mixing ment...

This chapter provides an overview of memory psychophysics. Psychophysics is the science that explicates the functional relations between physical stimuli and the resulting sensory responses. Memory psychophysics, or mnemophysics, is the branch of psychophysics that treats the functional relations between physical stimuli and their remembered sensor...

Five experiments explored how (a) perceived and remembered odor intensities relate to concentration; (b) odor intensities integrate in perceptual, memorial, and mentally constructed mixtures; and (c) components vary in intensity in physical versus mental mixtures. Ss estimated the magnitude of unmixed stimuli presented physically (perceptual estima...

Five experiments explored how (a) perceived and remembered odor intensities relate to concentration; (b) odor intensities integrate in perceptual, memorial, and mentally constructed mixtures; and (c) components vary in intensity in physical versus mental mixtures. Ss estimated the magnitude of unmixed stimuli presented physically (perceptual estima...

For groups of 10 subjects magnitude estimation of area presented physically or symbolically (using prelearned CVCs) could be described by power functions. Memorial judgments were also governed by power functions, but shallower ones. These relations held regardless of length of delay of the memory-based judgment.

In an attempt to measure how mode of response might affect psychophysical judgment, 18 subjects were asked to give magnitude estimates of the loudness of 1000-Hz tones at various sound pressure levels in each of two sessions. In one session, the subjects responded by giving their numerical judgments orally to the experimenter; in the other session,...