Cognition and perceptual disorders

Original Editor - Nupur Smit Shah Top Contributors - Nupur Smit Shah


Introduction[edit | edit source]

Cognition is the process of acquiring knowledge. It includes, reasoning, memory, awareness, judgement and intuition. Some authors include executive function under cognition too, such as problem solving, planning capacity, recognition of errors and abstract thinking. Many a times executive function is classified as higher level cognitive functions or metacognitive functions.

Perception is the integration of sensations into information that is meaningful in terms of psychology. It is the ability to choose the stimuli that need attention and action, to integrate them with each other and to interpret them.

Perception and sensation are not the same and should not be confused with each other. Sensation is defined as the awareness of stimuli through eyes, ears, nose etc., internal receptions or the peripheral cutaneous system. And perception is far more complex than the individual sensation.[1]

Perception disorders[edit | edit source]

Body image impairments[edit | edit source]

Unilateral neglect-[edit | edit source]

It is reported nearly in 25% of the stroke patients who are referred for rehabilitation. It is commonly associated with right parietal lesions.

Rehabilitation- The major goals here is to improve the attention of the neglected side along with proprioception and kinesthesia. The recent techniques of rehabilitation is neck muscle vibration, virtual reality, limb activation training, mental imagery training, TENS, Eye patching, vestibular rehabilitation and mirror therapy.[2]

Anosognosia-[edit | edit source]

It is the denial of illness that may be seen in the patients of head injury. The patients presents either lack of concern about the deficit or verbal denial of their illness.[3]They don't realize the benefits of rehabilitation and are not willing to undergo any treatment. Visual field defect, apathy and unable to identify the pictures are the common in anosognosia.[4]It is commonly seen in neurological conditions such as Hemiplegia and Alzheimer's disease.[5]

Rehabilitation- As per evidence , Vestibular stimulation can be given in anosognosia.[2]

Somatoagnosia-[edit | edit source]

There is lack of awareness of the body structure. The patient even doesn't understand the relationship of body parts with oneself or to others. They may not be able to imitate the movements of the therapist.[1]They deny the existence of their body part and is also known as autotopagnosia.[6]

Right and left discrimitation- The patient cannot discriminate between the commands of right and left handed task.

Finger agnosia- In this condition the client doesn't indicate, name , select/ differentiate the fingers of their own hand. It happens in the patients of cerebral lesion.[7]

Spatial Relation impairments[edit | edit source]

Figure ground discrimitation-[edit | edit source]

Here the patient cannot select and segregate the elements from the background by the visual system.[8]

Form discrimitation-[edit | edit source]

Inability to identify objects of similar shapes. For example if you ask to identify two similar objects such as an orange and a ball the patient will not be able to identify/differentiate it.

Spatial Relation-[edit | edit source]

The patient is not able to locate things properly and cannot understand its relation with one another in space and with oneself. For example , he cannot set a dinning table properly and doesn't place spoon, bowl, plate appropriately.

Position in space-[edit | edit source]

The patient is unable to understand spatial concepts of up-down ,front-back, out-in. If he is told to kick a ball kept in front of him via his right leg, he will not know what to do.

Depth and distance perception-[edit | edit source]

The patient doesn't understand where to put the leg during stair climbing. He cannot judge how much water to pour into the glass and keeps pouring even after the glass gets filled.

Topographical disorientation-[edit | edit source]

The patient has difficulty to commute from one location to the other and doesn't understand the relationship of one location to the other. For example, the patient cannot find his own bedroom in the house.

The lesion is at the right retrosplenial cortex.

Vertical disorientation-[edit | edit source]

Anything which is vertical, appears tilted to the patient .There is lesion in nondominant parietal lobe. If he is given a task of holding a cane, he will not hold it in a straight position, it will be tilted.[1]

Rehabilitation

Virtual reality training programs are applied on the patients with spatial relation impairments and studies have shown that it enhances the spatial cognition and it is as effective as real world training.[9]

Agnosia[edit | edit source]

There is failure of recognition. Commonly see in neurodegenerative diseases.[10]

Tactile agnosia[edit | edit source]

The tactile perceptions are intact but the patient cannot recognize the objects via palpation. There is parietal lobe lesion (unilateral/bilateral). The somatosensory functions, intellectual ability, linguistic capacity and attention is appropriate. Rehabilitaton- Fabers approach of manipulation is used in tactile agnosia. The manipulation of the object is done with both the hands with or without visual stimuli.

Auditory agnosia[edit | edit source]

Hearing ability is intact but there impairment in sound perception. Such patients have intact language and cognitive function.[11] Rehabilitation- Lip reading and communication technique is applied in the clients of auditory agnosia.

Visual object agnosia[edit | edit source]

The patient cannot name the objects/faces/words presented in front of him. For example, the patient may call the bicycle , a pie.It can be assessed by copying /drawing of figures.[12]

Rehabilitation- Compensatory strategies and restorative training is applied in visual object agnosia.

Apraxia[edit | edit source]

It is a disorder in which the patient cannot perform skilled actions.[10]

Ideomotor apraxia[edit | edit source]

Loss of ability to imitate hand gestures. The client understands the requirements but cannot execute appropriate movements. There occurs errors in gesture production.

Ideational apraxia[edit | edit source]

There is transitive difficulty where the client doesn't understand the correct concept of the task. Faces difficulties like sequencing the tasks and the usage of objects.[13]

Rehabilitation- The tasks are broken down into various components. Each component is taught at once and practiced. Visual and auditory feedback is proved to be effective. Once the individual tests are learnt properly ,the physiotherapist add the complex movement pattern steadily.[2]

Cognitive deficits[edit | edit source]

Attention Deficit Disorders[edit | edit source]

Attention issues are commonly seen after stroke.[14] They are common among the ones who have right brain damage. [15]The attention system has connection with various cognitive functions like cognition, activity performance, language , memory and spatial organization hence attention deficits can highly affect the functional abilities of the person at home or at work.[14]

After the cerebrovascular accident, focused attention(selective) deficit gets cured in majority of the patients but higher order attentional problems may persist later. This includes, speed of processing, divided attention, working memory and vigilance.[16]

Neuropsychological assessment is used to classify the patients with cognitive issues like language, attention and memory.[17]

Selective attention[edit | edit source]

Also known as focused attention. The capacity to do the task in presence of visual, auditory or environmental stimuli.[1]It is needed when the patient has to ignore certain stimuli.

For example, The patient stops the activity of dressing while talking to the therapist/by stander. Here, the focused attention is affected.

Sustained attention[edit | edit source]

The capacity to address relevant information during the activity. The patient can respond effectively during the task.[1]

Divided attention[edit | edit source]

The patient has the capacity to respond to two or more tasks at a time.

Alternating attention[edit | edit source]

The capacity to do multiple tasks appropriately.[1]

Rehabilitation -In attention disorders patient, simple tasks are started initially and practiced several times. Slowly the complexity is added by the therapist.

Memory[edit | edit source]

Memory decline is common after stroke and affects the functional ability of the person. There are various memory deficits like long term memory loss, short term memory loss and immediate recall. Over all deterioration of memory is referred to as dementia. Rehabilitation- Memory rehabilitation which is a part of cognitive rehabilitation plays an important role in such patients. Here the use of internal and external aids can be done. Internal aids consist of mental imagery, pneumonic and rehearsal. External aids consist of notice boards, diaries, lists in order to help them recall and restore the memory.[18]






References[edit | edit source]

  1. 1.0 1.1 1.2 1.3 1.4 1.5 O'Sullivan SB, Schmitz TJ, Fulk G. Physical rehabilitation. FA Davis; 2019 Jan 25.
  2. 2.0 2.1 2.2 Surya N, Someshwar H. Rehabilitation in Perceptual disorders in stroke patients.
  3. Heilman KM. Anosognosia: possible neuropsychological mechanisms. Awareness of deficit after brain injury: Clinical and theoretical issues. 1991 Jan 24:53-62.
  4. Cutting J. Study of anosognosia. Journal of Neurology, Neurosurgery & Psychiatry. 1978 Jun 1;41(6):548-55.
  5. Bisiach E, Vallar G, Perani D, Papagno C, Berti A. Unawareness of disease following lesions of the right hemisphere: anosognosia for hemiplegia and anosognosia for hemianopia. Neuropsychologia. 1986 Jan 1;24(4):471-82.
  6. Nathanson M, Bergman PS, Gordon GG. Denial of illness: its occurrence in one hundred consecutive cases of hemiplegia. AMA Archives of Neurology & Psychiatry. 1952 Sep 1;68(3):380-7.
  7. Gerstmann J. Syndrome of finger agnosia, disorientation for right and left, agraphia and acalculia: local diagnostic value. Archives of Neurology & Psychiatry. 1940 Aug 1;44(2):398-408.
  8. Schnabel UH, Bossens C, Lorteije JA, Self MW, de Beeck HO, Roelfsema PR. Figure-ground perception in the awake mouse and neuronal activity elicited by figure-ground stimuli in primary visual cortex. Scientific reports. 2018 Dec 12;8(1):1-4.
  9. Kober SE, Wood G, Hofer D, Kreuzig W, Kiefer M, Neuper C. Virtual reality in neurologic rehabilitation of spatial disorientation. Journal of neuroengineering and rehabilitation. 2013 Dec;10(1):1-3.
  10. 10.0 10.1 Coslett HB. Apraxia, neglect, and agnosia. Continuum: Lifelong Learning in Neurology. 2018 Jun 1;24(3):768-82.
  11. Shell AR. Auditory agnosia. Handbook of clinical neurology. 2015 Jan 1;129:573-87.
  12. Coslett HB. Apraxia, neglect, and agnosia. Continuum: Lifelong Learning in Neurology. 2018 Jun 1;24(3):768-82.
  13. Clark D. Strategies to Cope with Cognitive Difficulties After a Stroke (SCOPE–Apraxia) (Doctoral dissertation, The University of Manchester (United Kingdom)).
  14. 14.0 14.1 Žagavec BS, Lešnik VM, Goljar N. Training of selective attention in work-active stroke patients. International Journal of Rehabilitation Research. 2015 Dec 1;38(4):370-2.
  15. Lincoln N, Majid M, Weyman N. Cognitive rehabilitation for attention deficits following stroke. Cochrane Database of Systematic Reviews. 2000(4).
  16. Michel JA, Mateer CA. Attention rehabilitation following stroke and traumatic brain injury. Europa medicophysica. 2006 Mar;42(1):59-67.
  17. Nøkleby K, Boland E, Bergersen H, Schanke AK, Farner L, Wagle J, Wyller TB. Screening for cognitive deficits after stroke: a comparison of three screening tools. Clinical rehabilitation. 2008 Dec;22(12):1095-104.
  18. das Nair R, Cogger H, Worthington E, Lincoln NB. Cognitive rehabilitation for memory deficits after stroke. Cochrane Database of Systematic Reviews. 2016(9).