Head-Restrained Lever Go/NoGo Visual Discrimination Task with Visiomode v2

This protocol is an adaptation of Michelle's lever Go/NoGo auditory discrimination task, which uses visual instead of auditory stimuli. Water-restricted, headplated mice learn to discriminate between a target and a distractor stimulus presented serially in pseudo-random order, pushing a lever to indicate when the target stimulus appears. The protocol is designed for across-learning recordings, and as such the inter-trial interval and stimulus interval remain constant throughout. Correction trials are also enabled throughout the duration of the protocol. The task in implemented in the Visiomode platform, using the lever apparatus for response input instead of the touchscreen. This protocol uses the Citric Acid Water Restriction protocol with sucrose rewards, instead of the traditional water deprivation protocol.

Attention and distraction in the modular visual system of a jumping spider

Animals must selectively attend to relevant stimuli and avoid being distracted by unimportant stimuli. Jumping spiders (Salticidae) do this by coordinating eyes with different capabilities. Objects are examined by a pair of high-acuity principal eyes, whose narrow field of view is compensated for by retinal movements. The principal eyes overlap in field of view with motion-sensitive anterior-lateral eyes, which direct their gaze to new stimuli. Using a salticid-specific eyetracker, we monitored the gaze direction of the principal eyes as they examined a primary stimulus. We then presented a distractor stimulus visible only to the ALEs and observed whether the principal eyes reflexively shifted their gaze to it or whether this response was flexible. Whether spiders redirected their gaze to the distractor depended on properties of both the primary and distractor stimuli. This flexibility suggests that higher-order processing occurs in the management of the attention of the principal eyes.

Identity-Based Crossmodal Negative Priming: Aftereffects of Ignoring in One Sensory Modality on Responding to Another Sensory Modality

Negative Priming (NP) refers to the phenomenon that responses towards previously ignored stimuli, as compared to new stimuli, are impaired. That is, NP is reflected in the performance on the probe display of a prime–probe sequence. NP is established in vision, audition and touch. In the current study, we presented participants with auditory, visual, and tactile manifestations of the same temporal patterns in order to measure NP across the senses. On each trial, the sensory modality shifted from the prime to the probe. Each prime and probe display consisted of a target and a distractor stimulus, presented to the same sensory modality. On some trials, the prime distractor repeated as probe target (ignored-repetition trials), on other trials the probe stimuli had not been involved in the prime display (control trials). We observed NP between audition and touch (Experiment 1) and between vision and audition (Experiment 2). These findings indicate that the processes underpinning NP can operate at an amodal, postperceptual level.

The Simon Effect With Saccadic Eye Movements

In the Simon effect performance is faster and more accurate when the task-irrelevant spatial dimension of the stimulus corresponds to the location of the response, compared to when they do not correspond. In the prosaccade-antisaccade effect the latencies of saccades away from the stimulus location (i.e., antisaccades) are slower than the latencies of saccades toward the stimulus location (i.e., prosaccades). Because these two effects share a similar basis, the study of the Simon effect with saccadic eye movements needs to be decoupled from the prosaccade-antisaccade effect. A standard Simon task (Experiment 1) and a Simon task in which a distractor stimulus was also presented (Experiment 2) were implemented. In Experiment 1, results showed an effect likely attributable to the sum of the Simon effect and the prosaccade-antisaccade effect. In Experiment 2, in which the difference between the prosaccade and antisaccade was eliminated, only a Simon effect, cognitive in nature, manifested itself.

Working memory performance and neural activity in prefrontal cortex of peripubertal monkeys

The dorsolateral prefrontal cortex matures late into adolescence or early adulthood. This pattern of maturation mirrors working memory abilities, which continue to improve into adulthood. However, the nature of the changes that prefrontal neuronal activity undergoes during this process is poorly understood. We investigated behavioral performance and neural activity in working memory tasks around the time of puberty, a developmental event associated with the release of sex hormones and significant neurological change. The developmental stages of male rhesus monkeys were evaluated with a series of morphometric, hormonal, and radiographic measures. Peripubertal monkeys were trained to perform an oculomotor delayed response task and a variation of this task involving a distractor stimulus. We found that the peripubertal monkeys tended to abort a relatively large fraction of trials, and these were associated with low levels of task-related neuronal activity. However, for completed trials, accuracy in the delayed saccade task was high and the appearance of a distractor stimulus did not impact performance significantly. In correct trials delay period activity was robust and was not eliminated by the presentation of a distracting stimulus, whereas in trials that resulted in errors the sustained cue-related activity was significantly weaker. Our results show that in peripubertal monkeys the prefrontal cortex is capable of generating robust persistent activity in the delay periods of working memory tasks, although in general it may be more prone to stochastic failure than in adults.

The Influence of Distractors on Saccade-Target Selection: Saccade Trajectory Effects

It has long been known that the path (trajectory) taken by the eye to land on a target is rarely straight (Yarbus, 1967). Furthermore, the magnitude and direction of this natural tendency for curvature can be modulated by the presence of a competing distractor stimulus presented along with the saccade target. The distractor-related modulation of saccade trajectories provides a subtle measure of the underlying competitive processes involved in saccade target selection. Here we review some of our own studies into the effects distractors have on saccade trajectories, which can be regarded as a way of probing the competitive balance between target and distractor salience.

Attentional Effects on Adaptation of Rotary Motion in the Plane

The effect of attention on the adaptation effects produced by stimuli rotating in the picture plane was examined in five experiments. In experiment 1, subjects performed a task either on a rotating adapting stimulus or on an irrelevant distractor stimulus. Adaptation of a subsequent ambiguous test stimulus was greater when the adapting stimulus was attended than when the irrelevant stimulus was attended. In experiments 2, 3, and 5, two adapting stimuli were presented, rotating in opposite directions, and subjects attended to one or the other. The direction of rotation of the ambiguous test stimulus depended on which adapting stimulus was attended. In experiment 4, the influence of eye movements in producing adaptation in ambiguous motion displays was determined by contrasting the effects of adaptation produced by dual adaptation stimuli rotating in the same or opposite direction. Adaptation effects were not predicted by eye movement hypotheses.

On Consolidation and the Potency of Delayed Stimulus Suffixes

In a strictly serial recall task, increasing the temporal separation of a spoken memory list and a spoken distractor (stimulus suffix) is known to reduce the latter's potency as a source of interference. This phenomenon was studied further using suffix delays in the range 0.8–6.4 s and a transcription task to minimize rehearsal during the suffix delay. The results indicated that the probability of correct recall from the terminal serial position, of a sequence of eight digits, is a linearly increasing function of the logarithm of the suffix delay, over the range studied. The results are discussed in terms of their value as evidence for the existence of a consolidation process.