It has been believed for some time that inputs from different sensory organs are processed in different areas in the brain. Using functional neuroimaging, it can be seen that sensory-specific cortices are activated by different inputs. For example, regions in the occipital cortex are tied to vision and those on the superior temporal gyrus are recipients of auditory inputs. There exist studies suggesting deeper multisensory convergences than those at the sensory-specific cortices, which were listed earlier. This convergence of multiple sensory modalities is known as sensory integration.
Sensory integration deals with how the brain processes sensory input from multiple sensory modalities. These include the five classic senses of vision (sight), audition (hearing), tactile stimulation (touch), olfaction(smell), and gustation (taste). Other sensory modalities exist, for example the vestibular sense (balance and the sense of movement) and proprioception (the sense of knowing one’s position in space). It is important that the information of these different sensory modalities must be relatable. The sensory inputs themselves are in different electrical signals, and in different contexts[4]. Through sensory integration, the brain can relate all sensory inputs into a coherent percept, upon which our interaction with the environment is ultimately based.
[edit]Basic structures involved
The different senses were always thought to be controlled by separate lobes of the brain[5]. The lobes of the brain are the classifications that divide the brain both anatomically and functionally[6]. These lobes are the Frontal lobe, responsible for conscious thought, Parietal lobe, responsible for visuospatial processing, the Occipital lobe, responsible for the sense of sight, and the temporal lobe, responsible for the senses of smell and sound. From the earliest times of neurology, it has been thought that these lobes are solely responsible for their one sensory modality input[7]. However, newer research has shown that that may not entirely be the case.
[edit]Problems with sensory integration
Sometimes there can be a problem with the encoding of the sensory information. This disorder is known as sensory integration dysfunction, or SID. This disorder can be further classified into three main types. Type 1 is when the patient exhibits a sensory modulation disorder, where he/she seek sensory stimulation due to an over or under response to sensory stimuli. Type 2 is when the patient exhibits a sensory based motor disorder. Patients who have this type of SID have incorrect processing of motor information that leads to poor motor skills. Type 3 sensory integration dysfunction occurs when the patient has a sensory discrimination disorder, which is characterized by postural control problems, lack of attentiveness, and disorganization. There are several therapies used to treat SID. Dr. A. Jean Ayres claimed that a child needs a healthy “sensory diet,” which is all of the activities that a child performs that gives him/her the necessary sensory inputs that he/she needs to get the brain into better performing sensory integration.