Related Experiment Video
Updated: May 23, 2026
07:13
A Two-interval Forced-choice Task for Multisensory Comparisons
Published on: November 9, 2018
Conversion of sensory signals into perceptual decisions
Ranulfo Romo1, Victor de Lafuente
1Instituto de Fisiología Celular-Neurociencias, Universidad Nacional Autónoma de México, 04510 México, D.F., Mexico. rromo@ifc.unam.mx
Progress in Neurobiology
|April 5, 2012
Summary
This study reveals how the brain processes sensory information through multiple cortical areas. It shows how tactile stimuli are represented, maintained in working memory, and compared to make decisions.
Area of Science:
- Neurobiology
- Cognitive Neuroscience
Background:
- Understanding how the brain encodes sensory information for perception, memory, and decision-making is a key challenge.
- The cerebral cortex processes sensory input through interconnected regions.
Purpose of the Study:
- To investigate how sensory stimuli are represented across different cortical areas.
- To elucidate the neural mechanisms underlying working memory and perceptual decision-making.
Main Methods:
- Electrophysiological recordings in monkeys performing a tactile comparison task.
- Analysis of neuronal activity in somatosensory, parietal, prefrontal, and premotor cortices.
Main Results:
- Sensory stimuli activate multiple cortical areas, with information becoming more related to perception and decisions as it progresses.
- Somatosensory cortex generates a parameterized tactile representation maintained in working memory by frontal areas.
- Decision-related activity emerges across prefrontal, premotor, and parietal cortices during stimulus comparison.
- Neuronal populations with opposite tuning suggest a subtraction mechanism for comparing sensory information.
Conclusions:
- Cortical circuits dynamically represent and transform sensory information for higher cognitive functions.
- A subtraction-based mechanism may underlie perceptual decision-making by comparing sensory inputs.
Related Concept Videos
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Perception is a fundamental psychological process that enables individuals to organize, interpret, and consciously experience sensory information. This process is crucial for understanding and interacting with the world around us. It includes both bottom-up and top-down processing, each playing a distinct role in how we perceive our environment.
Bottom-up processing begins at the sensory level, where receptors detect external environmental stimuli. These could include the tactile sensation of...
Bottom-up processing begins at the sensory level, where receptors detect external environmental stimuli. These could include the tactile sensation of...
01:11Sensory Perception: Organization of the Somatosensory System
The somatosensory system is the central and peripheral nervous system component that senses and processes touch, pressure, pain, temperature, and body position or proprioception. The process of sensation takes place at three levels:
The receptor level:
The receptor level is the first stage of sensation. It involves the detection of a stimulus by specialized sensory receptors. The stimulus must arrive within the receptor's receptive field. Next, the receptor converts the energy of the stimulus...
The receptor level:
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01:26Introduction to Special Senses
Sensory receptors play an integral part in comprehending our external and internal environments. They receive diverse stimuli, converting them into the nervous system's electrochemical signals. This conversion occurs as the stimulus alters the sensory neuron's cell membrane potential, instigating the generation of an action potential. This action potential is subsequently transmitted to the central nervous system (CNS), which integrates with other sensory data or higher cognitive functions.
01:21Sensation
Sensory receptors are specialized neurons that respond to specific types of external stimuli, initiating the process known as sensation. This occurs when sensory input, such as light entering the eye, is detected by these receptors, causing chemical changes in the cells of the retina. These cells then convert the sensory stimulus into action potentials that are transmitted to the central nervous system, a process termed transduction.
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01:26Visual System
Light enters the eye through the cornea, a transparent, dome-shaped surface covering the surface of the eyeball that helps to direct and focus incoming light. This light is then channeled toward the pupil, an adjustable opening whose size is controlled by the iris. The iris, a pigmented muscle, regulates the amount of light entering the eye by contracting or dilating the pupil, thereby ensuring optimal light levels for clear vision.
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01:31What is a Sensory System?
Sensory systems detect stimuli—such as light and sound waves—and transduce them into neural signals that can be interpreted by the nervous system. In addition to external stimuli detected by the senses, some sensory systems detect internal stimuli—such as the proprioceptors in muscles and tendons that send feedback about limb position.