Brain signal complexity rises with repetition suppression in visual learning.
نویسندگان
چکیده
Neuronal activity associated with visual processing of an unfamiliar face gradually diminishes when it is viewed repeatedly. This process, known as repetition suppression (RS), is involved in the acquisition of familiarity. Current models suggest that RS results from interactions between visual information processing areas located in the occipito-temporal cortex and higher order areas, such as the dorsolateral prefrontal cortex (DLPFC). Brain signal complexity, which reflects information dynamics of cortical networks, has been shown to increase as unfamiliar faces become familiar. However, the complementarity of RS and increases in brain signal complexity have yet to be demonstrated within the same measurements. We hypothesized that RS and brain signal complexity increase occur simultaneously during learning of unfamiliar faces. Further, we expected alteration of DLPFC function by transcranial direct current stimulation (tDCS) to modulate RS and brain signal complexity over the occipito-temporal cortex. Participants underwent three tDCS conditions in random order: right anodal/left cathodal, right cathodal/left anodal and sham. Following tDCS, participants learned unfamiliar faces, while an electroencephalogram (EEG) was recorded. Results revealed RS over occipito-temporal electrode sites during learning, reflected by a decrease in signal energy, a measure of amplitude. Simultaneously, as signal energy decreased, brain signal complexity, as estimated with multiscale entropy (MSE), increased. In addition, prefrontal tDCS modulated brain signal complexity over the right occipito-temporal cortex during the first presentation of faces. These results suggest that although RS may reflect a brain mechanism essential to learning, complementary processes reflected by increases in brain signal complexity, may be instrumental in the acquisition of novel visual information. Such processes likely involve long-range coordinated activity between prefrontal and lower order visual areas.
منابع مشابه
Running Head : LEARNING TRAJECTORIES IN THE INFANT BRAIN 1 Tracing Trajectories of Audio - visual Learning in the Infant Brain
Although infants begin learning about their environment before they are born, little is known about how the infant brain changes during learning. Here, we take the initial steps in documenting how the neural responses in the brain change as infants learn to associate audio and visual stimuli. Using functional near-infrared spectroscopy (fNRIS) to record hemodynamic responses in the infant corte...
متن کاملRepetition suppression in occipitotemporal cortex despite negligible visual similarity: evidence for postperceptual processing?
The reduced neural response in certain brain regions when a task-relevant stimulus is repeated ("repetition suppression", RS) is often attributed to facilitation of the cognitive processes performed in those regions. Repetition of visual objects is associated with RS in the ventral and lateral occipital/temporal regions, and is typically attributed to facilitation of visual processes, ranging f...
متن کاملNeural Basis of Repetition Priming during Mathematical Cognition: Repetition Suppression or Repetition Enhancement?
We investigated the neural basis of repetition priming (RP) during mathematical cognition. Previous studies of RP have focused on repetition suppression as the basis of behavioral facilitation, primarily using word and object identification and classification tasks. More recently, researchers have suggested associative stimulus-response learning as an alternate model for behavioral facilitation...
متن کاملThe Influence of Affective Variables on the Complexity, Accuracy, and Fluency in L2 Oral Production: The Contribution of Task Repetition
The main purpose of the study reported in this paper was to examine the interrelationships between L2 risk-taking, English learning motivation, L2 speaking anxiety, linguistic confidence, and low-proficiency English as a foreign language (EFL) learners’ speaking complexity, accuracy, and fluency (CAF). A secondary purpose was to test whether task repetition can influence the level of the mentio...
متن کاملTracing trajectories of audio-visual learning in the infant brain.
Although infants begin learning about their environment before they are born, little is known about how the infant brain changes during learning. Here, we take the initial steps in documenting how the neural responses in the brain change as infants learn to associate audio and visual stimuli. Using functional near-infrared spectroscopy (fNRIS) to record hemodynamic responses in the infant corte...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Neuroscience
دوره 326 شماره
صفحات -
تاریخ انتشار 2016