Transcript Topic 22
Biology 463 - Neurobiology Topic 22 Attention and Mental Illness Lange Attention: • Attention is the cognitive process of selectively concentrating on one aspect of the environment while ignoring other things • Attention also is referred to as the allocation of processing resources. • Attention is one of the most intensely studied topics within cognitive neuroscience. • Attention remains a major area of investigation within education, psychology and neuroscience. A relatively new body of research is investigating the phenomenon of traumatic brain injuries and their effects on attention. In head injury, a coup injury occurs under the site of impact with an object, and a contrecoup injury occurs on the side opposite the area that was impacted. Coma as a means to study attention. One of the most used models for the evaluation of attention in patients with very different neurologic pathologies is the model of Sohlberg and Mateer. Their hierarchic model is based on studies using the recovering of attention processes of brain damage patients after coma. Five different kinds of activities of growing difficulty are described in the model; connecting with the activities those patients could do as their recovering process advanced: • Focused attention: The ability to respond discretely to specific visual, auditory or tactile stimuli. • Sustained attention (vigilance): The ability to maintain a consistent behavioral response during continuous and repetitive activity. • Selective attention: The ability to maintain a behavioral or cognitive set in the face of distracting or competing stimuli. Therefore it incorporates the notion of "freedom from distractibility.“ • Alternating attention: The ability of mental flexibility that allows individuals to shift their focus of attention and move between tasks having different cognitive requirements. • Divided attention: This is the highest level of attention and it refers to the ability to respond simultaneously to multiple tasks or multiple task demands. Hemispatial Neglect • a neuropsychological condition in which, after damage to one hemisphere of the brain, a deficit in attention to and awareness of one side of space is observed • commonly on the opposite side of the damaged hemisphere • most strikingly affecting visual perception (‘visual neglect’ as in the above image), neglect in other forms of perception can occur • A patient with neglect behaves as if one side of sensory space is nonexistent • A patient with neglect might fail to eat the food on the one half of their plate, even though they complain of being hungry • If someone with neglect is asked to draw a clock, their drawing might show only the numbers 12 and 1 to 6, the other side being distorted or left blank. • Neglect patients may also ignore one side of their body, shaving or adding make-up only to the non-neglected side. Mental Illness: • Psychiatry • Branch of medicine concerned with the diagnosis and treatment of disorders that affect the mind or psyche • Psychiatric disorders • Examples: Anxiety disorders, affective disorders, schizophrenia Anxiety Disorders • Fear – An adaptive response to threatening situations – Innate and species-specific – Learned • Anxiety disorders – Caused by inappropriate expression of fear Anxiety Disorders - a group of mental disorders characterized by excessive feelings of anxiety and/or fear, where anxiety is worry about future events and fear is a reaction to current events. • Common Anxiety Disorders: – Panic disorder - characterized by recurring severe panic attacks. It may also include significant behavioral changes lasting at least a month and of ongoing worry about the implications or concern about having other attacks. – Agoraphobia - characterized by anxiety in situations where the sufferer perceives certain environments as dangerous or uncomfortable, often due to the environment's vast openness or crowdedness. – Obsessive-compulsive disorder - characterized by intrusive thoughts that produce uneasiness, apprehension, fear, or worry; by repetitive behaviors aimed at reducing the associated anxiety; or by a combination of such obsessions and compulsions. - Generalized anxiety disorder - characterized by excessive, uncontrollable and often irrational worry. For diagnosis of this disorder, symptoms must last at least six months. - Post-traumatic stress disorder – characterized as a disorder that may develop after a person is exposed to one or more traumatic events, such as sexual assault, serious injury, or the threat of death. Associated with many of the above anxiety disorders is one or more forms of clinical depressive illness: Depressive illness is characterized by a pervasive and persistent low mood that is accompanied by low self-esteem and by a loss of interest or pleasure in normally enjoyable activities. Anxiety Disorders are often coupled to aspects of Depressive Illness at the biochemical level • Treatments for Chemically Based Depressive Illnesses often Employs Antidepressant Medications Chemical treatments for Affective Disorders Using Lithium: • • • Lithium compounds are used as mood-stabilizing drugs primarily in the treatment of bipolar disorder. Lithium has a role in the treatment of the mania aspect of bipolar disorder both acutely and in the long term Lithium has also been shown to reduce the risk of suicide or suicide attempts in bipolar patients. The first clinical trials of the use of lithium occurred in the 1960s. END.