Dissociable roles of the anterior temporal regions in successful encoding of memory for person identity information.
ABSTRACT Memory for person identity information consists of three main components: face-related information, name-related information, and person-related semantic information, such as the person's job title. Although previous studies have demonstrated the importance of the anterior temporal lobe (ATL) in the retrieval of associations between these kinds of information, there is no evidence concerning whether the ATL region contributes to the encoding of this memory, and whether ATL roles are dissociable between different levels of association in this memory. Using fMRI, we investigated dissociable roles within the ATL during successful encoding of this memory. During encoding, participants viewed unfamiliar faces, each paired with a job title and name. During retrieval, each learned face was presented with two job titles or two names, and participants were required to choose the correct job title or name. Successful encoding conditions were categorized by subsequent retrieval conditions: successful encoding of names and job titles (HNJ), names (HN), and job titles (HJ). The study yielded three main findings. First, the dorsal ATL showed greater activations in HNJ than in HN or HJ. Second, ventral ATL activity was greater in HNJ and HJ than in HN. Third, functional connectivity between these regions was significant during successful encoding. The results are the first to demonstrate that the dorsal and ventral ATL roles are dissociable between two steps of association, associations of person-related semantics with name and with face, and a dorsal-ventral ATL interaction predicts subsequent retrieval success of memory for person identity information.
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ABSTRACT: Group functional magnetic resonance imaging (fMRI) studies suggest that anxiety disorders are associated with anomalous brain activation and functional connectivity (FC). However, brain-based features sensitive enough to discriminate individual subjects with a specific anxiety disorder and that track symptom severity longitudinally, desirable qualities for putative disorder-specific biomarkers, remain to be identified. Blood oxygen level-dependent (BOLD) fMRI during emotional face perceptual tasks and a new, large-scale and condition-dependent FC and machine learning approach were used to identify features (pair-wise correlations) that discriminated patients with social anxiety disorder (SAD, N=16) from controls (N=19). We assessed whether these features discriminated SAD from panic disorder (PD, N=16), and SAD from controls in an independent replication sample that performed a similar task at baseline (N: SAD=15, controls=17) and following 8-weeks paroxetine treatment (N: SAD=12, untreated controls=7). High SAD vs HCs discrimination (area under the ROC curve, AUC, arithmetic mean of sensitivity and specificity) was achieved with two FC features during unattended neutral face perception (AUC=0.88, P<0.05 corrected). These features also discriminated SAD vs PD (AUC=0.82, P=0.0001) and SAD vs HCs in the independent replication sample (FC during unattended angry face perception, AUC=0.71, P=0.01). The most informative FC was left hippocampus-left temporal pole, which was reduced in both SAD samples (replication sample P=0.027), and this FC increased following the treatment (post>pre, t(11)=2.9, P=0.007). In conclusion, SAD is associated with reduced FC between left temporal pole and left hippocampus during face perception, and results suggest promise for emerging FC-based biomarkers for SAD diagnosis and treatment effects.Neuropsychopharmacology advance online publication, 2 October 2013; doi:10.1038/npp.2013.211.Neuropsychopharmacology: official publication of the American College of Neuropsychopharmacology 08/2013; · 8.68 Impact Factor
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ABSTRACT: We meta-analyzed imaging studies on theory of mind and formed individual task groups based on stimuli and instructions. Overlap in brain activation between all task groups was found in the mPFC and in the bilateral posterior TPJ. This supports the idea of a core network for theory of mind that is activated whenever we are reasoning about mental states, irrespective of the task- and stimulus-formats (Mar, 2011). In addition, we found a number of task-related activation differences surrounding this core-network. ROI based analyses show that areas in the TPJ, the mPFC, the precuneus, the temporal lobes and the inferior frontal gyri have distinct profiles of task-related activation. Functional accounts of these areas are reviewed and discussed with respect to our findings.Neuroscience & Biobehavioral Reviews 01/2014; · 10.28 Impact Factor
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ABSTRACT: The uncinate fasciculus is a bidirectional, long-range white matter tract that connects lateral orbitofrontal cortex and Brodmann area 10 with the anterior temporal lobes. Although abnormalities in the uncinate fasciculus have been associated with several psychiatric disorders and previous studies suggest it plays a putative role in episodic memory, language and social emotional processing, its exact function is not well understood. In this review we summarize what is currently known about the anatomy of the uncinate, we review its role in psychiatric and neurological illnesses, and we evaluate evidence related to its putative functions. We propose that an overarching role of the uncinate fasciculus is to allow temporal lobe-based mnemonic associations (e.g. an individual's name + face + voice) to modify behaviour through interactions with the lateral orbitofrontal cortex, which provides valence-based biasing of decisions. The bidirectionality of the uncinate fasciculus information flow allows orbital frontal cortex-based reward and punishment history to rapidly modulate temporal lobe-based mnemonic representations. According to this view, disruption of the uncinate may cause problems in the expression of memory to guide decisions and in the acquisition of certain types of learning and memory. Moreover, uncinate perturbation should cause problems that extend beyond memory to include social-emotional problems owing to people and objects being stripped of personal value and emotional history and lacking in higher-level motivational value.Brain 05/2013; · 9.92 Impact Factor