Behavioral Choice-related neuronal activity in monkey primary somatosensory cortex in a haptic delay task

East China Normal University, Shanghai.
Journal of Cognitive Neuroscience (Impact Factor: 4.09). 03/2012; 24(7):1634-44. DOI: 10.1162/jocn_a_00235
Source: PubMed


The neuronal activity in the primary somatosensory cortex was collected when monkeys performed a haptic-haptic DMS task. We found that, in trials with correct task performance, a substantial number of cells showed significant differential neural activity only when the monkeys had to make a choice between two different haptic objects. Such a difference in neural activity was significantly reduced in incorrect response trials. However, very few cells showed the choice-only differential neural activity in monkeys who performed a control task that was identical to the haptic-haptic task but did not require the animal to either actively memorize the sample or make a choice between two objects at the end of a trial. From these results, we infer that the differential activity recorded from cells in the primary somatosensory cortex in correct performance reflects the neural process of behavioral choice, and therefore, it is a neural correlate of decision-making when the animal has to make a haptic choice.

1 Follower
18 Reads
  • [Show abstract] [Hide abstract]
    ABSTRACT: Microelectrode recordings of cortical activity in primates performing working memory tasks reveal some cortical neurons exhibiting sustained or graded persistent elevations in firing rate during the period in which sensory information is actively maintained in short-term memory. These neurons are called "memory cells". Imaging and transcranial magnetic stimulation studies indicate that memory cells may arise from distributed cortical networks. Depending on the sensory modality of the memorandum in working memory tasks, neurons exhibiting memory-correlated patterns of firing have been detected in different association cortices including prefrontal cortex, and primary sensory cortices as well. Here we elaborate on neurophysiological experiments that lead to our understanding of the neuromechanisms of working memory, and mainly discuss findings on widely distributed cortical networks involved in tactile working memory.
    Journal of Physiology-Paris 06/2013; 107(6). DOI:10.1016/j.jphysparis.2013.06.001 · 1.90 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The role that posterior parietal (PPC) and motor cortices play in modulating neural responses in somatosensory areas 1 and 2 was examined using reversible deactivation by transient cooling. Multiunit recordings from neurons in areas 1 and 2 were collected from 6 anesthetized adult monkeys (Macaca mulatta) before, during, and following reversible deactivation of areas 5L, 7b, or motor cortex (M1/PM), while select locations on the hand and forelimb were stimulated. Response changes were quantified as increases and decreases to stimulus-driven activity relative to baseline and analyzed during 3 recording epochs: During deactivation ("cool"), and at two time points after deactivation ("rewarm", "rewarm2"). Although the type of response change observed was variable, for neurons at the recording sites tested, over 90% exhibited a significant change in response during cooling of 7b while cooling area 5L or M1/PM produced a change in 75% and 64% of sites, respectively. These results suggest that regions in the PPC, and to a lesser extent motor cortex, shape the response characteristics of neurons in areas 1 and 2 and that this kind of feedback modulation is necessary for normal somatosensory processing. Further, this modulation appears to happen on a minute-by-minute basis and may serve as the substrate for phenomena such as somatosensory attention.
    Journal of Neurophysiology 08/2014; 112(10). DOI:10.1152/jn.00141.2014 · 2.89 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Previous studies have shown that neurons of monkey dorsolateral prefrontal cortex (DLPFC) integrate information across modalities and maintain it throughout the delay period of working-memory (WM) tasks. However, the mechanisms of this temporal integration in the DLPFC are still poorly understood. In the present study, to further elucidate the role of the DLPFC in crossmodal WM, we trained monkeys to perform visuo-haptic (VH) crossmodal and haptic-haptic (HH) unimodal WM tasks. The neuronal activity recorded in the DLPFC in the delay period of both tasks indicates that the early-delay differential activity probably is related to the encoding of sample information with different strengths depending on task modality, that the late-delay differential activity reflects the associated (modality-independent) action component of haptic choice in both tasks (that is, the anticipation of the behavioral choice and/or active recall and maintenance of sample information for subsequent action), and that the sustained whole-delay differential activity likely bridges and integrates the sensory and action components. In addition, the VH late-delay differential activity was significantly diminished when the haptic choice was not required. Taken together, the results show that, in addition to the whole-delay differential activity, DLPFC neurons also show early- and late-delay differential activities. These previously unidentified findings indicate that DLPFC is capable of (i) holding the coded sample information (e.g., visual or tactile information) in the early-delay activity, (ii) retrieving the abstract information (orientations) of the sample (whether the sample has been haptic or visual) and holding it in the late-delay activity, and (iii) preparing for behavioral choice acting on that abstract information.
    Proceedings of the National Academy of Sciences 12/2014; 112(2). DOI:10.1073/pnas.1410130112 · 9.67 Impact Factor