Psychophysical investigation of vigilance decrement in jumping spiders: overstimulation or understimulation?

The inability to maintain signal detection performance with time on task, or vigilance decrement, is widely studied in people because of its profound implications on attention-demanding tasks over sustained periods of time (e.g., air-traffic control). According to the resource depletion (overload) theory, a faster decrement is expected in tasks that are cognitively demanding or overstimulating, while the underload theory predicts steeper decrements in tasks that provide too little cognitive load, or understimulation. Using Trite planiceps, a jumping spider which is an active visual hunter, we investigated vigilance decrement to repetitive visual stimuli. Spiders were tethered in front of two stimulus presentation monitors and were given a polystyrene ball to hold. Movement of this ball indicates an attempt to turn towards a visual stimulus presented to a pair of laterally facing (anterior lateral) eyes for closer investigation with high acuity forward-facing (anterior median) eyes. Vigilance decrement is easily measured, as moving visual stimuli trigger clear optokinetic responses. We manipulated task difficulty by varying the contrast of the stimulus and the degree of ‘noise’ displayed on the screen over which the stimulus moved, thus affecting the signal:noise ratio. Additionally, we manipulated motivation by paired testing of hungry and sated spiders. All factors affected the vigilance decrement, but the key variable affecting decrement was stimulus contrast. Spiders exhibited a steeper decrement in the harder tasks, aligning with the resource depletion theory.     

Transcendence,transmission and transformation: the transcendent function in infant observation

Abstract: This article discusses the activation of the transcendent function as it operates through a series of complex parallel processes occurring within a Tavistock Model Infant Observation Group whose location is Palo Alto, California. We follow the observer, a seasoned female analyst, through her final two observations as she is caught initially in the central family complex that does not allow for a conscious ending to this three‐year observational period. Subsequently through the work of the transcendent function within the group, a discussion of the observer's ensuing paradoxical enactment takes place as we watch how this observer becomes able to help the family reach a termination not previously possible. Moving within a dynamic field that includes the infant observation group, the observed baby and his family, we experience the numinosity of the transformation that is activated. We will explore the ongoing encounter between the group mind, the observer and the observed as mutations within this dynamic field enable a genuine experience of mourning that has a profound effect on the observed baby and family.     

Care,play and lifelong learning

In this paper, links between the concepts of long-term care and lifelong learning are suggested, and notions of care and the author’s construction of the Pedagogic Third will be proposed. The psychoanalysis of children stresses the importance of symbolic play, during which the child uses games to master internal conflicts. Analogous results might emerge from play that engages adult learners. However, where play helps children define roles and accept rule-regulated behaviour, we consider to what extent an adult learner is addressing desires which cannot be satisfied because they are too threatening, or desires which cannot be satisfied in reality and which are represented symbolically in play as an alternative. In order to work through these ideas, we consider a comedic representation of a hospital ward and an extract from the diary of a midwife who was also a long-term patient. The author’s contribution to the conference was a workshop and not the presentation of a paper. As such, this paper has been written in retrospect and is consequently reflective in stance. Much of the work described in this paper is connected to a larger piece of work, a monograph in progress, due to be published in 2019.     

Temporal properties in masking biological motion

The perception of biological motion using point light animation techniques was investigated in several experiments. Animations simulating walking were presented with additional masking dots. The temporal properties of the walking motion or the temporal relationship between the walking and masking motions were systematically manipulated. Results showed that (1) perception of biological motion was sensitive to even small temporal perturbation within the walker, (2) the effectiveness of a mask depended upon the temporal phase difference between the mask and point light walker, (3) relatively small temporal differences between the mask and point light walker decreased the effectiveness of the mask, and (4) these effects were not due simply to observers detecting the phase offsets in the display. Temporal properties of the motion are important in perceiving the human form in action, just as in other types of figure-ground segregation. This information may be processed by both motion and form pathways for processing biological motion.     

A mutant mouse with a highly specific contextual fear-conditioning deficit found in an N-ethyl-N-nitrosourea (ENU) mutagenesis screen

Targeted mutagenesis in mice has shown that genes from a wide variety of gene families are involved in memory formation. The efficient identification of genes involved in learning and memory could be achieved by random mutagenesis combined with high-throughput phenotyping. Here, we provide the first report of a mutagenesis screen that has generated memory mutants in the mouse. We tested a group of N-ethyl-N-nitrosourea (ENU) mutagenized mice in the conditioned fear paradigm. We screened for both dominant and recessive mutations that caused impairments in contextual or tone fear conditioning. Heritability testing confirmed three fear conditioning mutants, i.e., Forgetful, Slowlearner, and Scatterbrain. All three have a learning or short-term memory deficit in contextual fear conditioning. Forgetful was further characterized and showed a highly specific phenotype. The contextual fear-conditioning deficit was apparent when Forgetful was trained with tone-shock pairings, but not when trained with shock alone. The deficit was not due to changes in shock sensitivity or anxiety. Forgetful was not impaired in two other memory tests (hidden platform version of Morris water maze and object recognition). Our data show that a mutagenesis screen can generate mutant mice with highly specific memory phenotypes that can supplement existing mice with targeted mutations. Mapping of Slowlearner found linkage to a region of chromosome 12 (LOD score of 6.5 close to D12Mit171), which suggests that ENU mutants should enable the positional cloning of genes involved in memory formation.     

The Work Design Questionnaire (WDQ): developing and validating a comprehensive measure for assessing job design and the nature of work

Although there are thousands of studies investigating work and job design, existing measures are incomplete. In an effort to address this gap, the authors reviewed the work design literature, identified and integrated previously described work characteristics, and developed a measure to tap those work characteristics. The resultant Work Design Questionnaire (WDQ) was validated with 540 incumbents holding 243 distinct jobs and demonstrated excellent reliability and convergent and discriminant validity. In addition, the authors found that, although both task and knowledge work characteristics predicted satisfaction, only knowledge characteristics were related to training and compensation requirements. Finally, the results showed that social support incrementally predicted satisfaction beyond motivational work characteristics but was not related to increased training and compensation requirements. These results provide new insight into how to avoid the trade-offs commonly observed in work design research. Taken together, the WDQ appears to hold promise as a general measure of work characteristics that can be used by scholars and practitioners to conduct basic research on the nature of work or to design and redesign jobs in organizations.     

Status,testosterone, and human intellectual performance: stereotype threat as status concern

Results from two experiments suggest that stereotype-threat effects are special cases of a more general process involving the need to maintain or enhance status. We hypothesized thatsituations capable of confirming a performance stereotype might representeither a threat to status or an opportunity for enhancement of status,depending on the nature of the stereotype. The positive relationship betweenbaseline testosterone and status sensitivity led us to hypothesize that hightestosterone levels in males and females would amplify existing performanceexpectations when gender-based math-performance stereotypes were activated.In Study 1, high-testosterone females performed poorly on a math test when anegative performance stereotype was primed. In Study 2, high-testosteronemales excelled on a math test when a positive performance stereotype wasprimed. The moderating effect of testosterone on performance suggests that astereotype-relevant situation is capable of conferring either a loss or again of status on targets of the stereotype.     

Pattern-contingent color aftereffects on noninduced patterns

In a series of experiments, we found that in addition to expected reports of color aftereffects on patterns viewed during induction, reliable and predictable reports of color were given by subjects to patterns they did not view during induction. These reports to noninduced patterns were generally to patterns that were orthogonal to the patterns seen during induction. Induction with, for example, a red vertical grating led to appropriate aftereffects (i.e., green) on that vertical pattern and to the complementary aftereffect (i.e., pink) on a horizontal grating. We suggest that such color aftereffects on noninduced patterns are based on a shift in the activity of orientation coding mechanisms as a result of viewing the inducing patterns. We further propose that the results are consistent with the Lie transformation group theory of neuropsychology and that they add to a growing body of research demonstrating the applicability of this theory to the understanding of pattern-contingent color aftereffects.     

The role of structure in infant visual pattern perception

The research of the authors and others on the role of structure in infant visual pattern perception is reviewed. Two new experiments are reported on preference for symmetry in infants. It is shown that infants reliably prefer patterns with multiple axes of bilateral symmetry relative to asymmetrical patterns. Also, the results demonstrate that vertically oriented single axis bilateral symmetry is more salient than horizontally oriented symmetry in infants as it is in adults. It is argued that sensitivity to various kinds of pattern structure reflects fundamental operations of the visual system.     

Adjunctive brainstem behaviors in the rat

Adjunctive behaviors refers to behaviors that are “out of context” and/or excessive in amount. The terminology was first used for unexplained behaviors associated with food pellet ratio contingencies in food deprived rats (Falk, 1971). Clinically, unrelated and complex excessive behaviors were also noted with brainstem and diencephalic discharges (Andy, 1986, 1989 and 1995; Andy and Jurko, 1986). The objective of this study was to develop a model of brainstem generated adjunctive behaviors in the rat. Method: Sixty-one adult rats were used. Kindling was induced by mechanical and DC electrical perturbations in the midbrain. Nine different treatment groups were established in which lesions and drugs were used separately and in different combinations. Cocaine was used to accentuate, and dextrorphan to attenuate the kindling process. Behaviors were visually analyzed and recorded by video camera; they were not quantified. DC stimulation and EEGs were done with Grass instruments. Recording and stimulation sights were verified histologically. Results: A total of 45 different behaviors were elicited. DC stimulation kindled subjects had significantly more behaviors than did electrode insertion alone and cocaine alone. However, cocaine combined with DC stimulation increased the number and intensity of the kindled behaviors. Dextrorphan tended to facilitate catatonic and sleep states. Behaviors occurred randomly and were unrelated, even when they occurred in clusters. The behaviors were associated with four abnormal EEG discharge patterns. Conclusion: We speculate that brainstem behaviors are innate adjunctive drives that are generated in the brainstem reticular formation. They are monitored by the cortex and partially modified by environmental and cortical inputs.