Individual differences reveal similarities in serial dependence effects across perceptual tasks, but not to oculomotor tasks.

Serial dependence effects have been observed across a wide range of perceptual and oculomotor tasks. This opens up the question of whether these effects observed share underlying mechanisms. Here we measured serial dependence effects in a semipredictable environment for the same group of observers across four different tasks, two perceptual (color and orientation judgments) and two oculomotor (tracking moving targets and the pupil light reflex).

Double training reveals an interval-invariant subsecond temporal structure in the brain.

Subsecond temporal perception is critical for understanding time-varying events. Many studies suggest that subsecond timing is an intrinsic property of neural dynamics, distributed across sensory modalities and brain areas. However, our recent finding of the transfer of temporal interval discrimination (TID) learning across sensory modalities supports the existence of a more abstract and conceptual representation of subsecond time that guides the temporal processing of distributed mechanisms.

Crossmodal to unimodal transfer of temporal perceptual learning.

Subsecond temporal processing is crucial for activities requiring precise timing. Here, we investigated perceptual learning of crossmodal (auditory-visual or visual-auditory) temporal interval discrimination (TID) and its impacts on unimodal (visual or auditory) TID performance. The research purpose was to test whether learning is based on a more abstract and conceptual representation of subsecond time, which would predict crossmodal to unimodal learning transfer.

Macaque V1 responses to 2nd-order contrast-modulated stimuli and the possible subcortical and cortical contributions.

Natural images comprise contours and boundaries defined by 1st-order luminance-modulated (LM) cues that are readily encoded by V1 neurons, and 2nd-order contrast-modulated (CM) cues that carry local, but not over-the-space, luminance changes. The neurophysiological foundations for CM processing remain unsolved. Here we used two-photon calcium imaging to demonstrate that V1 superficial-layer neurons respond to both LM and CM gratings in awake, fixating, macaques, with overall LM responses stronger than CM responses.

A supramodal and conceptual representation of subsecond time revealed with perceptual learning of temporal interval discrimination.

Subsecond time perception has been frequently attributed to modality-specific timing mechanisms that would predict no cross-modal transfer of temporal perceptual learning. In fact, perceptual learning of temporal interval discrimination (TID) reportedly shows either no cross-modal transfer, or asymmetric transfer from audition to vision, but not vice versa. However, here we demonstrate complete cross-modal transfer of auditory and visual TID learning using a double training paradigm.

Functional organization of spatial frequency tuning in macaque V1 revealed with two-photon calcium imaging.

V1 neurons are functionally organized in orientation columns in primates. Whether spatial frequency (SF) columns also exist is less clear because mixed results have been reported. A definitive solution would be SF functional maps at single-neuron resolution.

Orientation Tuning and End-stopping in Macaque V1 Studied with Two-photon Calcium Imaging.

Orientation tuning is a fundamental response property of V1 neurons and has been extensively studied with single-/multiunit recording and intrinsic signal optical imaging. Long-term 2-photon calcium imaging allows simultaneous recording of hundreds of neurons at single neuron resolution over an extended time in awake macaques, which may help elucidate V1 orientation tuning properties in greater detail. We used this new technology to study the microstructures of orientation functional maps, as well as population tuning properties, in V1 superficial layers of 5 awake macaques.

Plaid Detectors in Macaque V1 Revealed by Two-Photon Calcium Imaging.

Neuronal responses to one-dimensional orientations are combined to represent two-dimensional composite patterns; this plays a key role in intermediate-level vision such as texture segmentation. However, where and how the visual cortex starts to represent composite patterns, such as a plaid consisting of two superimposing gratings of different orientations, remains neurophysiologically elusive. Psychophysical and modeling evidence has suggested the existence of early neural mechanisms specialized in plaid detection [1-6], but the responses of V1 neurons to an optimally orientated grating are actually suppressed by a superimposing grating of different orientation (i.

Myopic decisions under negative emotions correlate with altered time perception.

Previous studies have obtained inconsistent findings about emotional influence on inter-temporal choice (IC). In the present study, we first examined the effect of temporary emotional priming induced by affective pictures in a trial-to-trial paradigm on IC. The results showed that negative priming resulted in much higher percentages of trials during which smaller-but-sooner reward (SS%) were chosen compared with positive and neutral priming.

Neural substrate of initiation of cross-modal working memory retrieval.

Cross-modal working memory requires integrating stimuli from different modalities and it is associated with co-activation of distributed networks in the brain. However, how brain initiates cross-modal working memory retrieval remains not clear yet. In the present study, we developed a cued matching task, in which the necessity for cross-modal/unimodal memory retrieval and its initiation time were controlled by a task cue appeared in the delay period.