The Experts below are selected from a list of 227337 Experts worldwide ranked by ideXlab platform

Duje Tadin - One of the best experts on this subject based on the ideXlab platform.

  • Disentangling locus of perceptual Learning in the visual hierarchy of motion processing.
    Scientific reports, 2019
    Co-Authors: Ruyuan Zhang, Duje Tadin
    Abstract:

    Visual perceptual Learning (VPL) can lead to long-lasting perceptual improvements. One of the central topics in VPL studies is the locus of plasticity in the visual processing hierarchy. Here, we tackled this question in the context of motion processing. We took advantage of an established transition from component-dependent representations at the earliest level to pattern-dependent representations at the middle-level of cortical motion processing. Two groups of participants were trained on the same motion direction identification task using either grating or plaid stimuli. A set of pre- and post-training tests was used to determine the Degree of Learning specificity and generalizability. This approach allowed us to disentangle contributions from different levels of processing stages to behavioral improvements. We observed a complete bi-directional transfer of Learning between component and pattern stimuli that moved to the same directions, indicating Learning-induced plasticity associated with intermediate levels of motion processing. Moreover, we found that motion VPL is specific to the trained stimulus direction, speed, size, and contrast, diminishing the possibility of non-sensory decision-level enhancements. Taken together, these results indicate that, at least for the type of stimuli and the task used here, motion VPL most likely alters visual computation associated with signals at the middle stage of motion processing.

  • Disentangling locus of perceptual Learning in the visual hierarchy of motion processing
    2018
    Co-Authors: Ruyuan Zhang, Duje Tadin
    Abstract:

    Visual perceptual Learning (VPL) can lead to long-lasting perceptual improvements. While the efficacy of VPL is well established, there is still a considerable debate about what mechanisms underlie the effects of VPL. Much of this debate concentrates on where along the visual processing hierarchy behaviorally relevant plasticity takes place. Here, we aimed to tackle this question in context of motion processing, a domain where links between behavior and processing hierarchy are well established. Specifically, we took advantage of an established transition from component-dependent representations at the earliest level to pattern-dependent representations at the middle-level of cortical motion processing. We trained two groups of participants on the same motion direction identification task using either grating or plaid stimuli. A set of pre- and post-training tests was used to determine the Degree of Learning specificity and generalizability. This approach allowed us to disentangle contributions from both low- and mid-level motion processing, as well as high-level cognitive changes. We observed a complete bi-directional transfer of Learning between component and pattern stimuli as long as they shared the same apparent motion direction. This result indicates Learning-induced plasticity at intermediate levels of motion processing. Moreover, we found that motion VPL is specific to the trained stimulus direction, speed, size, and contrast, highlighting the pivotal role of basic visual features in VPL, and diminishing the possibility of non-sensory decision-level enhancements. Taken together, our study psychophysically examined a variety of factors mediating motion VPL, and demonstrated that motion VPL most likely alters visual computation in the middle stage of motion processing.

Nicolette A Hodyl - One of the best experts on this subject based on the ideXlab platform.

  • the cortisol awakening response is associated with performance of a serial sequence reaction time task
    International Journal of Psychophysiology, 2016
    Co-Authors: Nicolette A Hodyl, Luke A Schneider, Annmaree Vallence, Angela Clow, Michael C Ridding, Julia B Pitcher
    Abstract:

    There is emerging evidence of a relationship between the cortisol awakening response (CAR) and the neural mechanisms underlying Learning and memory. The aim of this study was to determine whether the CAR is associated with acquisition, retention and overnight consolidation or improvement of a serial sequence reaction time task. Salivary samples were collected at 0, 15, 30 and 45 min after awakening in 39 healthy adults on 2 consecutive days. The serial sequence reaction time task was repeated each afternoon. Participants completed the perceived stress scale and provided salivary samples prior to testing for cortisol assessment. While the magnitude of the CAR (Z score) was not associated with either baseline performance or the timed improvement during task acquisition of the serial sequence task, a positive correlation was observed with reaction times during the stable performance phase on day 1 (r=0.373, p=0.019). Residuals derived from the relationship between baseline and stable phase reaction times on day 1 were used as a surrogate for the Degree of Learning: these residuals were also correlated with the CAR mean increase on day 1 (r=0.357, p=0.048). Task performance on day 2 was not associated with the CAR obtained on this same day. No association was observed between the perceived stress score, cortisol at testing or task performance. These data indicate that a smaller CAR in healthy adults is associated with a greater Degree of Learning and faster performance of a serial sequence reaction time task. These results support recognition of the CAR as an important factor contributing to cognitive performance throughout the day.

Ruyuan Zhang - One of the best experts on this subject based on the ideXlab platform.

  • Disentangling locus of perceptual Learning in the visual hierarchy of motion processing.
    Scientific reports, 2019
    Co-Authors: Ruyuan Zhang, Duje Tadin
    Abstract:

    Visual perceptual Learning (VPL) can lead to long-lasting perceptual improvements. One of the central topics in VPL studies is the locus of plasticity in the visual processing hierarchy. Here, we tackled this question in the context of motion processing. We took advantage of an established transition from component-dependent representations at the earliest level to pattern-dependent representations at the middle-level of cortical motion processing. Two groups of participants were trained on the same motion direction identification task using either grating or plaid stimuli. A set of pre- and post-training tests was used to determine the Degree of Learning specificity and generalizability. This approach allowed us to disentangle contributions from different levels of processing stages to behavioral improvements. We observed a complete bi-directional transfer of Learning between component and pattern stimuli that moved to the same directions, indicating Learning-induced plasticity associated with intermediate levels of motion processing. Moreover, we found that motion VPL is specific to the trained stimulus direction, speed, size, and contrast, diminishing the possibility of non-sensory decision-level enhancements. Taken together, these results indicate that, at least for the type of stimuli and the task used here, motion VPL most likely alters visual computation associated with signals at the middle stage of motion processing.

  • Disentangling locus of perceptual Learning in the visual hierarchy of motion processing
    2018
    Co-Authors: Ruyuan Zhang, Duje Tadin
    Abstract:

    Visual perceptual Learning (VPL) can lead to long-lasting perceptual improvements. While the efficacy of VPL is well established, there is still a considerable debate about what mechanisms underlie the effects of VPL. Much of this debate concentrates on where along the visual processing hierarchy behaviorally relevant plasticity takes place. Here, we aimed to tackle this question in context of motion processing, a domain where links between behavior and processing hierarchy are well established. Specifically, we took advantage of an established transition from component-dependent representations at the earliest level to pattern-dependent representations at the middle-level of cortical motion processing. We trained two groups of participants on the same motion direction identification task using either grating or plaid stimuli. A set of pre- and post-training tests was used to determine the Degree of Learning specificity and generalizability. This approach allowed us to disentangle contributions from both low- and mid-level motion processing, as well as high-level cognitive changes. We observed a complete bi-directional transfer of Learning between component and pattern stimuli as long as they shared the same apparent motion direction. This result indicates Learning-induced plasticity at intermediate levels of motion processing. Moreover, we found that motion VPL is specific to the trained stimulus direction, speed, size, and contrast, highlighting the pivotal role of basic visual features in VPL, and diminishing the possibility of non-sensory decision-level enhancements. Taken together, our study psychophysically examined a variety of factors mediating motion VPL, and demonstrated that motion VPL most likely alters visual computation in the middle stage of motion processing.

Julia B Pitcher - One of the best experts on this subject based on the ideXlab platform.

  • the cortisol awakening response is associated with performance of a serial sequence reaction time task
    International Journal of Psychophysiology, 2016
    Co-Authors: Nicolette A Hodyl, Luke A Schneider, Annmaree Vallence, Angela Clow, Michael C Ridding, Julia B Pitcher
    Abstract:

    There is emerging evidence of a relationship between the cortisol awakening response (CAR) and the neural mechanisms underlying Learning and memory. The aim of this study was to determine whether the CAR is associated with acquisition, retention and overnight consolidation or improvement of a serial sequence reaction time task. Salivary samples were collected at 0, 15, 30 and 45 min after awakening in 39 healthy adults on 2 consecutive days. The serial sequence reaction time task was repeated each afternoon. Participants completed the perceived stress scale and provided salivary samples prior to testing for cortisol assessment. While the magnitude of the CAR (Z score) was not associated with either baseline performance or the timed improvement during task acquisition of the serial sequence task, a positive correlation was observed with reaction times during the stable performance phase on day 1 (r=0.373, p=0.019). Residuals derived from the relationship between baseline and stable phase reaction times on day 1 were used as a surrogate for the Degree of Learning: these residuals were also correlated with the CAR mean increase on day 1 (r=0.357, p=0.048). Task performance on day 2 was not associated with the CAR obtained on this same day. No association was observed between the perceived stress score, cortisol at testing or task performance. These data indicate that a smaller CAR in healthy adults is associated with a greater Degree of Learning and faster performance of a serial sequence reaction time task. These results support recognition of the CAR as an important factor contributing to cognitive performance throughout the day.

Nash Unsworth - One of the best experts on this subject based on the ideXlab platform.

  • individual differences in working memory capacity and Learning evidence from the serial reaction time task
    Memory & Cognition, 2005
    Co-Authors: Nash Unsworth
    Abstract:

    High and low working memory (WM) capacity individuals performed the serial reaction time task under both incidental and intentional Learning conditions to determine the role of WM capacity in the Learning of sequential information. WM capacity differences emerged in conditions of intentional but not incidental Learning, indicating that individual differences in WM capacity occur in tasks requiring some form of control, with little difference appearing on tasks that required relatively automatic processing. Furthermore, an index of Learning was significantly related to a measure of general fluid intelligence under intentional conditions only. Thus, the Degree of Learning was significantly related to higher order cognition, but only when intentional processing was emphasized.