Psychology Commons^™

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 …

"The Natural History Of Truth: The Neurobiology Of Belief", Neil Greenberg

Neil Greenberg

The pursuit of truth is woven into the fabric of every organism*. Any estimate of how best to survive and thrive in the reality in which we are immersed requires a sense of self, of the world, and of their relationship to each other. I wish to explore the idea that this pursuit has at its heart two complementary modes of reality testing utilizing separate cerebral systems which deal, respectively with the correspondence of experience with the world and the coherence of the experience with previous experiences: “is it real” and “does it fit?” At multiple levels of the nervous …

A Dissociation Between Perception And Action In The Material‐Weight Illusion, Gavin Buckingham, Jonathan Cant, Kai-Ling Kao, Melvyn Goodale

Gavin Buckingham

We examined what forces are applied to objects that elicit this illusion when they are lifted.We predicted that:

(1) Forces on early trials will scale to each participant’s expectations of how much a particular block will weigh ‐ excessive force will be applied to the metal block and insufficient force applied to the polystyrene block.

(2) Forces on later trials will scale to the real weight of each block ‐ identical levels of force applied to all the blocks.

(3) MWI will persist throughout ‐ polystyrene block will feel the heaviest, metal block will feel the lightest.

Grasping And Lifting Different Materials, Gavin Buckingham, Jonathan Cant, Melvyn Goodale

Gavin Buckingham

The material from which an object is made can determine how heavy it feels (Seashore, 1899). Interestingly, a metal block that has been adjusted to have the same size and mass as a polystyrene block will feel lighter than the polystyrene block. We recently showed that participants experiencing this material-weight illusion’ (MWI) do not apply forces that match their perceptual experience of heaviness ‐ just like in the size‐weight illusion ( Flanagan & Beltzner, 2000).

Our previous study showed that forces on early trials were scaled to each participant’s expectations of how much a particular block should weigh ‐ excessive …

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 (M_age = 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 …

Fitness And Action Monitoring: Evidence For Improved Cognitive Flexibility In Young Adults, Jason R. Themanson, Matthew B. Pontifex, Charles H. Hillman

Jason R. Themanson, Ph.D

To improve behavior, one must detect errors and initiate subsequent corrective adaptations. This action monitoring process has been widely studied, but little is known about how one may improve this aspect of cognition. To examine the relationship between cardiorespiratory fitness and action monitoring, we recorded the error-related negativity (ERN), an event-related brain potential believed to index action monitoring, as well as post-error behavioral indices of action monitoring from healthy young adults (18–25 years) who varied in cardiorespiratory fitness. These measures were collected during the execution of flanker tasks emphasizing response accuracy or speed to better assess the specificity of any …

Investigating Bimanual Coordination In Dominant And Non-Dominant Virtual Hands, Gavin Buckingham, David Carey

Gavin Buckingham

A bias in attention towards the dominant hand has been cited as a possible factor in the lateralisation of human bimanual coordination (Peters, 1981). A mirror was placed between the hands of 18 dextral participants performing rhythmic anti-phase movements. This set-up gave the appearance of a reflected virtual hand (moving in time with the un-occluded hand), in the same spatial location as the occluded left or right hand. This asymmetrical conflict between vision and action examined whether the left hand would show higher levels of error when replaced by a virtual right hand than the converse condition. Higher levels of …

Self-Efficacy Effects On Neuroelectric And Behavioral Indices Of Action Monitoring In Older Adults, Jason R. Themanson, Charles H. Hillman, Edward Mcauley, Sarah M. Buck, Shawna E. Doerksen, Katherine S. Morris, Matthew B. Pontifex

Jason R. Themanson, Ph.D

The relationships between self-efficacy (SE), i.e., beliefs in personal capabilities, and behavioral and neuroelectric (i.e., ERN, Pe) indices of action monitoring were investigated in 40 older adults (13 male) during the completion of a flanker paradigm performed under task conditions emphasizing either accuracy or speed. SE relative to task performance during both conditions was assessed prior to each cognitive task. Results indicated that high-SE older adults exhibited larger ERN and Pe amplitudes compared to low-SE older adults under the accuracy instruction condition. Additionally, a moderating effect of SE on the relationship between ERN and post-error response accuracy was revealed in …

Bimanual Coupling In Left And Right Space: Which Hand Is Yoked To Which?, Gavin Buckingham, Gordon Binsted, David Carey

Gavin Buckingham

• Reaching across the body into contralateral space with one hand incurs a substantial cost on various measures of performance, compared to ipsilateral reaches of a similar amplitude (Carey, Hargreaves, & Goodale, 1996).

• When reaching with both hands, unimanual asymmetries disappear.

-The hands take off and land concurrently (Kelso, Southard, & Goodman, 1979).

• To test if this ‘yoking’ is driven by the left or the right hand, participants performed reaches of different amplitudes.

• These reaches were made to the left or right side of space.

-Further increasing the unimanual (baseline) asymmetries that get wiped out by the …

Input Vs. Output Level Coupling Demonstrates Asymmetrical Attentional Biases, Gavin Buckingham, David Carey

Gavin Buckingham

The current study examined the performance of each limb as it reached across the body (the hard task), while yoked to it’s ipsilateral reaching counterpart (the easy task).

Asymmetries In Attention Toward The Dominant Hand: Input Or Output?, Gavin Buckingham, Julie Main, David Carey

Gavin Buckingham

Peters (1981) suggested that an asymmetrical bias in attention (toward the right hand of right handers) could account for many manual asymmetries in bimanual task performance. Support for this notion comes from Honda (1982), who demonstrated preferential monitoring of the dominant hand during a bimanual reaching task, while Buckingham and Carey (2007) observed shorter refractory periods (dwell time in a bimanual discontinuous double-step reaching task) for the right hand.

Recent evidence may indicate an intentional (i.e. selection related behaviour – motor attention) bias toward the dominant hand (Bestelmeyer & Carey, 2004). The current study tests the hypothesis that the right …

Attentional Vs. Intentional Biases In Hand Movements; Hand-Specific Coupling & Bimanual Reaching, Gavin Buckingham, David Carey

Gavin Buckingham

Most of the population is dextral, showing a clear preference for performing the vast majority of tasks with their right hand. Peters (1981) suggested that an asymmetrical bias in attention (toward the right hand in right handers) could account for many manual asymmetries in bimanual task performance, with the left hand unable to perform the attentionally demanding portion of the task. Likewise, Honda (1982) demonstrated preferential monitoring of the dominant hand during a bimanual reaching task. Recent evidence has also shown an intentional (i.e. output related motor attention) bias toward the dominant hand (Bestelmeyer & Carey, 2004), another possible factor …

Visual Adaptation To Masculine And Feminine Faces Influences Generalized Preferences And Perceptions Of Trustworthiness, Gavin Buckingham, Lisa Debruine, Anthony Little, Lisa Welling, Claire Conway, Bernard Tiddeman, Benedict Jones

Gavin Buckingham

Although previous studies of individual differences in preferences for masculinity in male faces have typically emphasized the importance of factors such as changes in levels of sex hormones during the menstrual cycle, other research has demonstrated that recent visual experience with faces also influences preferences for sexual dimorphism in faces. Adaptation to either masculine or feminine faces increases preferences for novel faces that are similar to those that were recently seen. Here, we replicate this effect and demonstrate that adaptation to masculine or feminine faces also influences the extent to which masculine faces are perceived as trustworthy. These adaptation effects …

Age And Physical Activity Influences On Action Monitoring During Task Switching, Jason R. Themanson, Charles H. Hillman, John J. Curtin

Jason R. Themanson, Ph.D

Behavioral and neuroelectric indices of action monitoring were compared for 53 high and low physically active older (60–71 years) and younger (18–21 years) adults during a task-switching paradigm in which they performed a task repeatedly or switched between two different tasks. The error-related negativity (ERN) of a response-locked event-related brain potential (ERP) and behavioral measures of response speed and accuracy were measured during the heterogeneous condition (switching randomly between two tasks) of the switch task. Results indicated that older adults exhibited a greater relative slowing in RT during heterogeneous blocks and smaller ERN amplitude compared to younger adults. Additionally, physical …

Homeland Security: Engaging The Frontlines - Symposium Proceedings, George H. Baker, Cheryl J. Elliott

George H Baker

The rise of the American homeland security endeavor under the leadership of the new Department of Homeland Security has been heralded by several major national strategy documents. These documents have served to organize efforts at top levels within the government and industry. However, the national strategy guidance is not getting to many organizations and people at the grass-roots level who can make the most difference in preventing attacks, protecting systems, and recovering from catastrophic events, viz. the general citizenry, private infrastructure owners, and local governments. To better understand grass-roots issues and solutions, James Madison University, in cooperation with the Federal …

Identifying Placebo Effects With Data From Clinical Trials, Anup Malani

Anup Malani

A medical treatment is said to have placebo effects if patients who are optimistic about the treatment respond better to the treatment. This paper proposes a simple test for placebo effects. Instead of comparing the treatment and control arms of a single trial, one should compare the treatment arms of two trials with different probabilities of assignment to treatment. If there are placebo effects, patients in the higher-probability trial will experience better outcomes simply because they believe that there is a greater chance of receiving treatment. This paper finds evidence of placebo effects in trials of antiulcer and cholesterol-lowering drugs.

From Faculty For Undergraduate Neuroscience: Encouraging Innovation In Undergraduate Neuroscience Education By Supporting Student Research And Faculty Development, Eric Wiertelak, J. C. Hardwick, M. Kerchner, B. Lom, J. J. Ramirez

Eric Wiertelak

No abstract provided.

Reflections On… Phase Shifting Under Different Visual Conditions, Gavin Buckingham, David Carey, Arash Sahraie

Gavin Buckingham

When two limbs are moved out of time (i.e. opposing muscle activation at each limb) in rhythmic oscillatory movements, there is a tendency at high frequencies for the movements to synchronise in the temporal domain, resulting in bilateral homologous muscle activation known as a ‘phase shift’ (Kelso, 1984). In an effort to determine the degree with which perception influences this phase shifting behaviour (Mechsner et al., 2001), a mirror can be placed between the hands of participants, parallel to their mid-saggital plane such that the reflected hand appeared in the place of the occluded hand. This paradigm can be used …

Visual Adaptation To Masculine And Feminine Faces Influences Generalized Preferences And Perceptions Of Trustworthiness, Gavin Buckingham, L. Debruine, A. Little, L. Welling, C. Conway, B. Tiddeman, B. Jones

Gavin Buckingham

We compared the effects of adaptation to faces varying in sexual dimorphism of shape on perceptions of the trustworthiness and attractiveness of masculine faces.

Cardiorespiratory Fitness And Acute Aerobic Exercise Effects On Neuroelectric And Behavioral Measures Of Action Monitoring, Jason R. Themanson, Charles H. Hillman

Jason R. Themanson, Ph.D

Cardiorespiratory fitness and acute aerobic exercise effects on cognitive function were assessed for 28 higher- and lower-fit adults during a flanker task by comparing behavioral and neuroelectric indices of action monitoring. The error-related negativity, error positivity, and N2 components, as well as behavioral measures of response speed, accuracy, and post-error slowing were measured following a 30-minute acute bout of treadmill exercise or following 30-minutes of rest. A graded maximal exercise test was used to measure cardiorespiratory fitness by assessing maximal oxygen uptake. Results indicated that higher-fit adults exhibited reduced error-related negativity amplitude, increased error positivity amplitude, and increased post-error response …

Ethological Aspects Of Stress In A Model Lizard, Anolis Carolinensis, Neil Greenberg

Neil Greenberg

Research on the stress response in reptiles can provide a useful comparative perspective for understanding how the constituent elements of the response can be put into service of diverse behavioral adaptations. A summary of the neural and endocrine causes and consequences of specific behavioral patterns seen in the small diurnal lizard, Anolis carolinensis, has provided a model for the exploration of the dynamics of autonomic and neurohormonal contributions to adaptive behavior. In this species, changes in body color provide indices of the flux of circulating stress relevant hormones, and are seen in situations from spontaneous exploration through agonistic behavior. Furthermore, …

Adaptive Functions Of The Corpus Striatum: The Past And Future Of The R-Complex, Neil Greenberg

Neil Greenberg

The basal ganglia is emerging from the shadow cast by the most conspicuous clinical expression of its dysfunction: motor disorders.What is revealed is the nexus of a widely distributed system which functions in integrating action with cognition, motivation, and affect. Prominent among non-motor functions are striatal involvement in building up of sequences of behavior into meaningful, goal-directed patterns and repertoires and the selection of appropriate learned or innate sequences in concert with their possible predictive control. Further, striatum seems involved in declarative and strategic memory (involving intentional recollection and the management of retrieved memories, respectively). Findings from reptile experiments indicate …

The Saurian Psyche Revisted: Lizards In Research, Neil Greenberg

Neil Greenberg

This essay is intended to guide researchers interested in lizards as prospective experimental models to identify an appropriate species for their research needs and to care for lizards in a manner that will not compromise their utility. Coupled with these is a concern for critical thinking about the ethical dimension of lizard research, one guide for which is to consider the intersection of human needs and lizard needs. Before proceeding further, several arbitrary premises must be made clear: 1. While wholly deserving of study because of their intrinsic interest, I will assume that the lizard research to be undertaken is …

Art, Science, Areté, Neil Greenberg

Neil Greenberg

No abstract provided.

Ethological Considerations In The Experimental Study Of Lizard Behavior, Neil Greenberg

Neil Greenberg

The importance of an ethological approach to the experimental study of an unfamiliar species is described and several of its problems discussed. The selection of units of behavior is a crucial first step in the development of a behavior inventory. The correlation of a behavioral unit with a particular context is necessary to ascribe function to that to that unit and to develop an ethogram. Methods of studying lizards under controlled conditions are described and discussed. Constraints on behavior that must be considered in an experimental study include the microclimate and its thermal qualities, food and water, shelter utilization, and …