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Articles 1 - 9 of 9

Full-Text Articles in Neurosciences

Living In A Material World: How Visual Cues To Material Properties Affect The Way That We Lift Objects And Perceive Their Weight, Gavin Buckingham, Jonathan Cant, Melvyn Goodale Nov 2009

Living In A Material World: How Visual Cues To Material Properties Affect The Way That We Lift Objects And Perceive Their Weight, Gavin Buckingham, Jonathan Cant, Melvyn Goodale

Gavin Buckingham

The visual properties of an object provide many cues as to the tensile strength, compliance, and density of the material from which it is made. However, it is not well understood how these implicit associations affect our perceptions of these properties and how they determine the initial forces that are applied when an object is picked up. Here we examine the effects of these cues on such forces by using the classic "material-weight illusion" (MWI). Grip and load forces were measured in three experiments as participants lifted cubes made from metal, wood, and expanded polystyrene. These cubes were adjusted to …


Adapting To Dynamic Stimulus-Response Values: Differential Contributions Of Inferior Frontal, Dorsomedial, And Dorsolateral Regions Of Prefrontal Cortex To Decision Making., Derek G V Mitchell, Qian Luo, Shelley B Avny, Tomasz Kasprzycki, Karanvir Gupta, Gang Chen, Elizabeth C Finger, R James R Blair Sep 2009

Adapting To Dynamic Stimulus-Response Values: Differential Contributions Of Inferior Frontal, Dorsomedial, And Dorsolateral Regions Of Prefrontal Cortex To Decision Making., Derek G V Mitchell, Qian Luo, Shelley B Avny, Tomasz Kasprzycki, Karanvir Gupta, Gang Chen, Elizabeth C Finger, R James R Blair

Brain and Mind Institute Researchers' Publications

Dorsomedial prefrontal cortex (dmPFC), dorsolateral prefrontal cortex (dlPFC), and inferior frontal gyrus (IFG) have all been implicated in resolving decision conflict whether this conflict is generated by having to select between responses of similar value or by making selections following a reversal in reinforcement contingencies. However, work distinguishing their individual functional contributions remains preliminary. We used functional magnetic resonance imaging to delineate the functional role of these systems with regard to both forms of decision conflict. Within dmPFC and dlPFC, blood oxygen level-dependent responses increased in response to decision conflict regardless of whether the conflict occurred in the context of …


Perirhinal Cortex Contributes To Accuracy In Recognition Memory And Perceptual Discriminations., Edward B O'Neil, Anthony D Cate, Stefan Köhler Jul 2009

Perirhinal Cortex Contributes To Accuracy In Recognition Memory And Perceptual Discriminations., Edward B O'Neil, Anthony D Cate, Stefan Köhler

Brain and Mind Institute Researchers' Publications

The prevailing view of the medial temporal lobe (MTL) holds that its structures are dedicated to long-term declarative memory. Recent evidence challenges this position, suggesting that perirhinal cortex (PRc) in the MTL may also play a role in perceptual discriminations of stimuli with substantial visual feature overlap. Relevant neuropsychological findings in humans have been inconclusive, likely because studies have relied on patients with large and variable MTL lesions. Here, we conducted a functional magnetic resonance imaging study in healthy individuals to determine whether PRc shows a performance-related involvement in perceptual oddball judgments that is comparable to its established role in …


Physical Activity And Neurocognitive Function Across The Lifespan, Jason Themanson, Charles Hillman, Sarah Buck May 2009

Physical Activity And Neurocognitive Function Across The Lifespan, Jason Themanson, Charles Hillman, Sarah Buck

Jason R. Themanson, Ph.D

No abstract provided.


Acute Aerobic Exercise Effects On Event-Related Brain Potentials, Jason Themanson, Charles Hillman, Matthew Pontifex Apr 2009

Acute Aerobic Exercise Effects On Event-Related Brain Potentials, Jason Themanson, Charles Hillman, Matthew Pontifex

Jason R. Themanson, Ph.D

No abstract provided.


Rightward Biases During Bimanual Reaching, Gavin Buckingham, David Carey Mar 2009

Rightward Biases During Bimanual Reaching, Gavin Buckingham, David Carey

Gavin Buckingham

Two experiments were carried out to investigate whether attention is biased toward the right hand of right handers during bimanual coordination (Peters 1981). A novel discontinuous double-step reaching task was developed, where right-handed participants executed a bimanual reach followed by a left or right hand unimanual reach. Asymmetries in the downtime between the bimanual and unimanual reach portions (the refractory period) were used to infer the direction of attention. A shorter right hand refractory period was found in the first experiment, indicating a rightward bias in attention. In a second experiment, shifting the focus of attention during the bimanual portion …


To See Or Not To See: Prestimulus Α Phase Predicts Visual Awareness, Kyle E. Mathewson, Gabriele Gratton, Monica Fabiani, Diane M. Beck, Tony Ro Mar 2009

To See Or Not To See: Prestimulus Α Phase Predicts Visual Awareness, Kyle E. Mathewson, Gabriele Gratton, Monica Fabiani, Diane M. Beck, Tony Ro

Publications and Research

We often fail to see something that at other times is readily detectable. Because the visual stimulus itself is unchanged, this variability in conscious awareness is likely related to changes in the brain. Here we show that the phase of EEG α rhythm measured over posterior brain regions can reliably predict both subsequent visual detection and stimulus-elicited cortical activation levels in a metacontrast masking paradigm. When a visual target presentation coincides with the trough of an α wave, cortical activation is suppressed as early as 100 ms after stimulus onset, and observers are less likely to detect the target. Thus, …


Aerobic Fitness And Cognitive Development: Event-Related Brain Potential And Task Performance Indices Of Executive Control In Preadolescent Children, Jason Themanson, Charles Hillman, Sarah Buck, Matthew Pontifex, Darla Castelli Jan 2009

Aerobic Fitness And Cognitive Development: Event-Related Brain Potential And Task Performance Indices Of Executive Control In Preadolescent Children, Jason Themanson, Charles Hillman, Sarah Buck, Matthew Pontifex, Darla Castelli

Scholarship

The relationship between aerobic fitness and executive control was assessed in 38 higher- and lower-fit children (Mage = 9.4 years), grouped according to their performance on a field test of aerobic capacity. Participants performed a flanker task requiring variable amounts of executive control while event-related brain potential responses and task performance were assessed. Results indicated that higher-fit children performed more accurately across conditions of the flanker task and following commission errors when compared to lower-fit children, whereas no group differences were observed for reaction time. Neuroelectric data indicated that P3 amplitude was larger for higher- compared to lower-fit children across …


Aerobic Fitness And Cognitive Development: Event-Related Brain Potential And Task Performance Indices Of Executive Control In Preadolescent Children, Jason R. Themanson, Charles H. Hillman, Sarah M. Buck, Matthew B. Pontifex, Darla M. Castelli Dec 2008

Aerobic Fitness And Cognitive Development: Event-Related Brain Potential And Task Performance Indices Of Executive Control In Preadolescent Children, Jason R. Themanson, Charles H. Hillman, Sarah M. Buck, Matthew B. Pontifex, Darla M. Castelli

Jason R. Themanson, Ph.D

The relationship between aerobic fitness and executive control was assessed in 38 higher- and lower-fit children (Mage = 9.4 years), grouped according to their performance on a field test of aerobic capacity. Participants performed a flanker task requiring variable amounts of executive control while event-related brain potential responses and task performance were assessed. Results indicated that higher-fit children performed more accurately across conditions of the flanker task and following commission errors when compared to lower-fit children, whereas no group differences were observed for reaction time. Neuroelectric data indicated that P3 amplitude was larger for higher- compared to lower-fit children …