Hippocampal theta-dependent eyeblink classical conditioning: coordination of a distributed learning system

Richard F. Thompson's study of the neurobiological substrates of learning and memory has been a career-long endeavor, chosen early and pursued with uncompromising depth and breadth. His systematic mapping of the major brain systems and mechanisms involved in eyeblink classical conditioning (EBCC) established the essential role of the cerebellum. Investigations of the interactions between the hippocampus and cerebellum are critically important to this literature, given the essential involvement of these structures in trace EBCC as well as an important modulatory role of the hippocampus in delay EBCC. Hippocampal theta (3-7Hz) oscillations are known to reflect a functional state that influences both the timing of unit firing and the potential for neural plasticity in the hippocampus and other structures. Herein we present a brief summary of research demonstrating the behavioral enhancement due to theta and the underlying neurobiological correlates in both hippocampus and cerebellum during EBCC. Hippocampal and cerebellar local field potentials (LFPs) show that these distantly interconnected brain structures become precisely synchronized when conditions favor rapid behavioral acquisition. Our results suggest a major role for theta in coordinating the widely distributed memory system for trace EBCC. These and other important findings reflect Thompson's own work and his early-career mentoring of scientists whose contributions to the EBCC literature have ensured his major and lasting impact on the neurobiology of learning and memory.     

Systematic influence of gaze position on pupil size measurement: analysis and correction

Cognitive effort is reflected in pupil dilation, but the assessment of pupil size is potentially susceptible to changes in gaze position. This study exemplarily used sentence reading as a stand-in for paradigms that assess pupil size in tasks during which changes in gaze position are unavoidable. The influence of gaze position on pupil size was first investigated by an artificial eye model with a fixed pupil size. Despite its fixed pupil size, the systematic measurements of the artificial eye model revealed substantial gaze-position-dependent changes in the measured pupil size. We evaluated two functions and showed that they can accurately capture and correct the gaze-dependent measurement error of pupil size recorded during a sentence-reading and an effortless z-string-scanning task. Implications for previous studies are discussed, and recommendations for future studies are provided.     

The Giessen virtual environment laboratory: human wayfinding and landmark salience

In our virtual environment laboratory, we focus on different topics in human spatial cognition with projects on landmark salience, route knowledge, and survey knowledge. Within this laboratory note, we provide an overview of previous, current, and future work with our virtual environment Squareland.     

The specificity of temporal expectancy: evidence from a variable foreperiod paradigm

In speeded choice tasks with variable foreperiods (FPs), individuals behaviourally adapt to various frequency manipulations. Adaptations have been shown to frequencies of different stimulus-response events, to frequencies of different foreperiods, and to frequencies of different event-foreperiod combinations. We have investigated how participants adapt to a situation where all three frequency manipulations are done simultaneously. Three variable foreperiod experiments are reported. In Experiment 1, one target (the peak distributed target) appeared particularly frequently after one particular FP (the peak foreperiod), while another target was less frequent and equally distributed over all foreperiods. In Experiment 2, the equally distributed target was overall more frequent than the peak distributed one. In both experiments, performance advantages for the peak distributed target were specific to the peak foreperiod, and performance advantages at the peak foreperiod were specific to the peak distributed targets. A third experiment showed that, when two differently frequent target are both equally distributed over FPs, the performance distribution over FPs is not significantly different between both targets. Together, the results suggest that participants were able to simultaneously and specifically adapt to frequency manipulations in events, foreperiods, and event-foreperiod combinations.     

Normal aging dampens the link between intrusive thoughts and negative affect in reaction to daily stressors

We charted daily variations in intrusive thoughts to gain access to adult age differences in affective reactivity to daily stressors. On 100 days, 101 younger and 103 older adults reported stressors, intrusive thoughts, and negative affect. Although increments in intrusive thoughts were similar in both age groups on days with stressors, older adults' negative affect increased less than younger adults' on such days. In addition, (a) levels of intrusive thoughts and negative affect across study time were positively associated; (b) days with increased thoughts were days with increased negative affect; and (c) experiencing above-average intrusive thoughts about stressors strengthened affective reactions to stress. Relative to younger adults, all three associations were reduced in older adults. We tentatively conclude that normal aging dampens the stress-induced link between intrusive thoughts and affect. This dampening may contribute to preserved affective well-being and reduced affective reactivity to daily stress in old age.     

Prejudice against Women Leaders: Insights from an Indirect Questioning Approach

Sex Roles - To avoid social disapproval in studies on prejudice against women leaders, participants might provide socially desirable rather than truthful responses. Using the Crosswise Model, an...     

Consequence and Normative Guidance

Logic, the tradition has it, is normative for reasoning. But is that really so? And if so, in what sense is logic normative for reasoning? As Gilbert Harman has reminded us, devising a logic and devising a theory of reasoning are two separate enterprises. Hence, logic's normative authority cannot reside in the fact that principles of logic just are norms of reasoning. Once we cease to identify the two, we are left with a gap. To bridge the gap one would need to produce what John MacFarlane has appropriately called a bridge principle, i.e. a general principle articulating a substantive and systematic link between logical entailment and norms of reasoning. This is Harman's skeptical challenge. In this paper I argue that Harman's skeptical challenge can be met. I show how candidate bridge principles can be systematically generated and evaluated against a set of well‐motivated desiderata. Moreover, I argue that bridge principles advanced by MacFarlane himself and others, for all their merit, fail to address the problem originally set forth by Harman and so do not meet the skeptical challenge. Finally, I develop a bridge principle that meets Harman's requirements as well as being substantive.     

The ideomotor principle and motor sequence acquisition: Tone effects facilitate movement chunking

Participants practiced short sequences of key presses; sequence length and response-effect mapping were the independent variables. Contingent, distinct key-effect relations were contrasted with either contingent but uniform or no response effects. In Experiment 1, tone effects were relevant as response-specific stimuli and also as effects. The sequence length effect for the tones group was reduced. In Experiment 2, participants were informed about the sequences to be executed and then given varying amounts of preparation time before the start signal. A reduction in the sequence length effect was observed, and initiation times and mean interresponse time (IRTs) were generally reduced in the tone group. Preparation time could compensate for some but not all of the latency reducing influence of the tone effects. The results are discussed with reference to ideomotor approaches to motor control, i.e., the notion that actions are represented in sensory format.     

TPL—KATS-card sort: A tool for assessing structural knowledge

The study of how individuals organize knowledge has been a popular endeavor for several decades. As a result, techniques have been developed to assess how individuals represent and organize knowledge internally. Although several conceptual knowledge elicitation methods have been developed and used to assess the organization of knowledge, their use is often labor intensive and time consuming. Presented here is a software tool that was developed to reduce the problems associated with manually administering the conceptual knowledge elicitation technique, or card sorting. The TPL—KATS-card sort software not only simplifies the administration of the task, but also adds features to the card-sorting task such as media insertion, time stamping, and instructorless administration. In the present article, an introduction to the card-sorting technique is provided, the new software tool is described, and the advantages of the software are detailed.