Related Experiment Video
Updated: Jun 30, 2026
10:05
A Large Lateral Craniotomy Procedure for Mesoscale Wide-field Optical Imaging of Brain Activity
Published on: May 7, 2017
Multiple parietal operculum subdivisions in humans: tactile activation maps.
Harold Burton1, Robert J Sinclair, Jason R Wingert
1Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, MO 63110, USA. harold@pcg.wustl.edu
Somatosensory & Motor Research
|September 30, 2008
Summary
This study mapped brain activity in the human posterior parietal operculum (PO) during tactile tasks. Findings reveal distinct responses in PO subdivisions (OP 1-4) to vibrotactile and surface stimulation, suggesting specialized processing.
Area of Science:
- Neuroscience
- Somatosensory system research
- Human brain imaging
Background:
- The posterior parietal operculum (PO) is crucial for processing somatosensory information.
- Understanding the functional organization of human PO subdivisions (OP 1-4) is essential for mapping tactile perception.
- Previous animal studies have identified somatosensory areas in homologous regions, but human functional mapping remains incomplete.
Purpose of the Study:
- To investigate blood-oxygen-level-dependent (BOLD) responses in human PO subdivisions (OP 1-4) during tactile stimulation.
- To differentiate the neural activity patterns evoked by vibrotactile stimulation versus surface texture discrimination tasks.
- To compare the functional organization of human PO with previously described somatosensory areas in animals.
Main Methods:
- Functional magnetic resonance imaging (fMRI) was used to measure BOLD responses in human participants.
- Participants performed four vibrotactile tasks focusing on vibration parameters (frequency, duration, attention).
- Participants performed four surface stimulation tasks involving discrimination of textures, shapes, and raised letters.
Main Results:
- Bilateral activity was observed in multiple somatosensory subdivisions of the human PO, potentially homologous to animal somatosensory areas.
- All PO subdivisions (OP 1-4) were activated, with OP 1 showing broad activation across tasks.
- Vibrotactile tasks elicited more restricted activity foci in PO subdivisions compared to surface stimulation tasks.
- Greater spatial extents of activity in OP 1 and OP 4 during surface rubbing tasks did not align with prior somatotopy findings for the second finger representation in S2.
- Varied activity distributions across PO subdivisions suggest differences in low-level perceptual and cognitive processing between tasks.
Conclusions:
- The human posterior parietal operculum (PO) exhibits complex, somatotopically organized activity patterns during tactile processing.
- Distinct functional roles for PO subdivisions (OP 1-4) are suggested by differential responses to vibrotactile and surface stimulation.
- Findings provide insights into the human somatosensory system and its organization within the PO, with implications for understanding tactile perception and its neural underpinnings.
Related Concept Videos
01:33Somatosensation
The somatosensory system relays sensory information from the skin, mucous membranes, limbs, and joints. Somatosensation is more familiarly known as the sense of touch. A typical somatosensory pathway includes three types of long neurons: primary, secondary, and tertiary. Primary neurons have cell bodies located near the spinal cord in groups of neurons called dorsal root ganglia. The sensory neurons of ganglia innervate designated areas of skin called dermatomes.
01:23Somatosensory, Motor, and Association Cortex
The somatosensory cortex in the parietal lobes is crucial for interpreting sensory data such as touch, temperature, and proprioception. The somatosensory cortex, situated in the parietal lobes, plays a vital role in interpreting sensory information like touch, temperature, and proprioception—awareness of body position. This specialized brain region features an organized structure wherein neurons at the top primarily process sensations originating from the lower body. In contrast, those at the...
01:14Motor and Sensory Areas of the Cortex
The cerebral cortex, the brain's outermost layer, is pivotal in processing complex cognitive tasks, emotions, and various sensory inputs and executing voluntary motor activities. This intricate structure is divided into three primary functional areas: the motor areas, sensory areas, and association areas.
Motor Areas
The motor areas located in the frontal lobe are central to controlling voluntary movements. This region is further subdivided into the primary motor cortex and the premotor cortex.
Motor Areas
The motor areas located in the frontal lobe are central to controlling voluntary movements. This region is further subdivided into the primary motor cortex and the premotor cortex.
01:21Association Areas of the Cortex
Association areas are regions of the cerebral cortex that do not have a specific sensory or motor function. Instead, they integrate and interpret information from various sources to enable higher cognitive processes such as memory, learning, and decision-making. Some key association areas include the following:
Prefrontal Association Area: This area is located in the frontal lobe and is involved in planning, decision-making, and moderating social behavior. It connects with primary motor areas,...
Prefrontal Association Area: This area is located in the frontal lobe and is involved in planning, decision-making, and moderating social behavior. It connects with primary motor areas,...
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:
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...
01:29Overview of Somatic Sensory Pathways
Somatic sensory or somatosensory pathways refer to the neural pathways that carry information related to touch, pressure, pain, temperature, and proprioception from the skin, muscles, tendons, and joints to the brain. These pathways involve several stages of processing and integration of sensory information.
The somatosensory system is divided into three main pathways: the dorsal (or posterior) column-medial lemniscus, spinothalamic (or anterolateral), and spinocerebellar pathways.
The dorsal...
The somatosensory system is divided into three main pathways: the dorsal (or posterior) column-medial lemniscus, spinothalamic (or anterolateral), and spinocerebellar pathways.
The dorsal...