Dissociable perceptual-learning mechanisms revealed by diffusion model analysis

People typically respond faster to a stimulus when it is accompanied by a task-irrelevant accessory stimulus presented in another perceptual modality. However, the mechanisms responsible for this accessory-stimulus effect are still poorly understood. We examined the effects of auditory accessory stimulation on the processing of visual stimuli using scalp electrophysiology (Experiment 1) and a diffusion model analysis (Experiment 2). In accordance with previous studies, lateralized readiness potentials indicated that accessory stimuli do not speed motor execution. Surface Laplacians over the motor cortex, however, revealed a bihemispheric increase in motor activation—an effect predicted by nonspecific arousal models. The diffusion model analysis suggested that accessory stimuli do not affect parameters of the decision process, but expedite only the nondecision component of information processing. Consequently, we conclude that accessory stimuli facilitate stimulus encoding. The visual P1 and N1 amplitudes on accessory-stimulus trials were modulated in a way that is consistent with multisensory energy integration, a possible mechanism for this facilitation.

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A diffusion model analysis of the effects of aging on letter discrimination.

Psychology and Aging ◽

10.1037/0882-7974.18.3.415 ◽

2003 ◽

Vol 18 (3) ◽

pp. 415-429 ◽

Cited By ~ 93

Author(s):

Anjali Thapar ◽

Roger Ratcliff ◽

Gail McKoon

Keyword(s):

Diffusion Model ◽

Model Analysis ◽

Effects Of Aging

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Perceptual Sequence Learning Is More Severely Impaired than Motor Sequence Learning in Patients with Chronic Cerebellar Stroke

Journal of Cognitive Neuroscience ◽

10.1162/jocn_a_00444 ◽

2013 ◽

Vol 25 (12) ◽

pp. 2207-2215 ◽

Cited By ~ 8

Author(s):

Georg Dirnberger ◽

Judith Novak ◽

Christian Nasel

Keyword(s):

Motor Learning ◽

Perceptual Learning ◽

Sequence Learning ◽

Procedural Learning ◽

Perceptual Information ◽

Healthy Controls ◽

Learning Mechanisms ◽

Cerebellar Stroke ◽

Stimulus Response ◽

Significant Motor

Patients with cerebellar stroke are impaired in procedural learning. Several different learning mechanisms contribute to procedural learning in healthy individuals. The aim was to compare the relative share of different learning mechanisms in patients and healthy controls. Ten patients with cerebellar stroke and 12 healthy controls practiced a visuomotor serial reaction time task. Learning blocks with high stimulus–response compatibility were exercised repeatedly; in between these, participants performed test blocks with the same or a different (mirror-inverted or unrelated) stimulus sequence and/or the same or a different (mirror-inverted) stimulus–response allocation. This design allowed to measure the impact of motor learning and perceptual learning independently and to separate both mechanisms from the learning of stimulus–response pairs. Analysis of the learning blocks showed that, as expected, both patients and controls improved their performance over time, although patients remained significantly slower. Analysis of the test blocks revealed that controls showed significant motor learning as well as significant visual perceptual learning, whereas cerebellar patients showed only significant motor learning. Healthy participants were able to use perceptual information for procedural learning even when the rule linking stimuli and responses had been changed, whereas patients with cerebellar lesions could not recruit this perception-based mechanism. Therefore, the cerebellum appears involved in the accurate processing of perceptual information independent from prelearned stimulus–response mappings.

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