User:SimonaDoc/sandbox

Cognitive rigidity refers to the mental inability or struggle to change one’s views, opinions, mindsets or behaviour. This definition encompasses a number of areas. Rigidity is associated with the perseveration of actions, difficulty switching from one type of activity to another or the usual order of activities. Cognitive rigidity mainly refers to a thinking style described as "black-and-white", which is characterized by an inability to adopt different perspectives and switch between them effortlessly. Psychological assessment used to measure cognitive rigidity includes mainly task-switching tests, where error is measured by increased reaction time between trials where strategies change. Task switching is associated with prefrontal cortex, specifically left. Cognitive rigidity can reach clinical significance and is typical for certain mental disorders, such as autism, obsessive–compulsive disorder, depression, and anorexia nervosa. There are techniques devised to reduce cognitive rigidity, which include mindfulness based meditation and cognitive remediation therapy. The ability to change modes of thought and hold several things in mind at once, inhibiting others is a vital aspect of learning. The ability to adapt one’s thinking style, change routine and see things from a different perspective facilitates socialization and coping abilities. Understanding the nature of rigidity in different psychopathologies will provide more knowledge about them and specify the neural underpinnings of cognitive rigidity.

Definitions
"A large amount of effort has been devoted to the study of rigidity. Yet there is still little agreement as to its identity or its components." Cognitive rigidity was first seen as a neurological state of mind which an individual entered and where he remained but also as a way of resisting progress and finally a personality trait or characteristic. It happens that people get stuck in a certain way of doing things. However, there is a point when these strategies are no longer comfortable or beneficial and people realize that they are incapable of making changes, transfers and lose the ability to move on or alter their thoughts, therefore are rigid to a clinically significant degree. In some states or disorders, affected people do not accept alternatives to situations, perspectives or new approaches. Rigid thinking works within the boundaries of “either-or” and good or bad but nothing in between.

The Wisconsin card sorting test
The Wisconsin card sorting test determines the capability to switch task-relevant problem-solving strategies, which is often problematic in cognitive rigidity. Participants sort cards according to colour, quantity, and shape, based on right/wrong indications from the experimenter. They have to match a pile of cards with the rules changing constantly. Participants need to be able to adapt quickly, the number of cards it takes them to adapt to new rules is counted, which is correlated positively with rigidity levels.

Iowa gambling task
The Iowa gambling task is a computerised card game and is used to test decision-making skills. Participants are dealt four card decks on a computer screen. They are encouraged to ask for cards and the computer randomly generates cards that either wins or lose them money. Participants are encouraged to win as much as they can and get a reward every time they do but are also penalized sometimes for losing. Losing decks have distinct number of trials, so some decks are profitable and some are loss-making. Participants with rigid thinking style can struggle with the fact that the good and bad decks are randomly changing, which demands that they adapt to change.

Stroop test
In the Stroop test, participants have to read out loud what they see on a card or press a button on a computerised task. They are shown words and colours in different combinations, such as simply reading out words in print, identifying colours or the more complex trials where the word for a certain colour is printed in a conflicting colour (e.g. the word BLUE printed in green). In some trials, they have to report the colour and ignore the word and vice versa. Participants exhibiting cognitive rigidity can take a longer time on conflicting trials and in trials where the rules for reporting colour/word change fast.

Hayling sentence completion test
In the Hayling sentence completion test, participants are asked to complete the endings to a started sentence. These sentences have very obvious endings so in the first round participants generate the expected answers, whereas in the other round they are asked to come up with a nonsense ending by saying something completely unrelated. This task is used to investigate an individual’s ability to inhibit automatic responses and be creative in the process. Participants with rigid thinking can have difficulty with inhibition and violating the rules of normality by creating nonsense sentences.

Autism spectrum disorders
Patients diagnosed with Asperger’s syndrome or autism often exhibit rigid and inflexible thinking style and behaviour. They are unable to switch between emotional states; it is difficult to distract them once they are engaged in an emotion or activity. It is also problematic to change their routines as any alteration in a schedule causes anxiety. Autism spectrum disorders (ASD) are characterized by abnormal social behaviour, communication, restricted and repetitive interests caused by cognitive rigidity, resulting in the perseverance of a consistent and monotonous life. There is a hypothesis that acetyl-cholinergic systems may underlie autism-related symptoms and that a higher concentration of acetylcholine in the synaptic cleft might ameliorate such symptoms. This was tested on mice and confirmed, higher levels of acetylcholine reduced cognitive rigidity and enhanced social interaction. Research proved that the cholinergic system plays a significant role in in the etiology of ASD and increase in cognitive flexibility enhances social attention.

Anorexia nervosa
Anorexia nervosa (AN) is a type of eating disorder, classified under mental illnesses. It manifests itself usually by intense fear of body fat, gaining weight and body dysmorphia as a result of which patients restrict their food intake and become dangerously underweight. Patients suffering from this illness show certain traits pointing to cognitive rigidity, such as a rigid attention to food and body image, obsessive, inflexible personality and set of beliefs they follow, unable to change them. Research proved that their cognitive flexibility was reduced compared to healthy subjects on tasks such as Iowa Gambling task and Hayling Sentence Completion test. Patients were unable to inhibit automatic responses and establish a flexible strategy. Cognitive rigidity was proposed as a biological marker for AN. However, more extensive, longitudinal research is required to evaluate these propositions and eliminate confounds.

Obsessive–compulsive disorder and unipolar depression
Patients suffering from obsessive–compulsive disorder (OCD) experience obsessions, which are repeated, insistent and invasive thoughts, urges and compulsions that cause distress and are extremely difficult to avoid or ignore. Patients suffering from unipolar depression have an inclination to ruminate, which means that they continually ponder about the reasons, resulting effects and symptoms of their mood disorder. Researching rigidity in these two pathologies is important because if the rigidity is similar in nature, then it could be considered a risk factor for these illnesses and strategies for reducing this rigidity could be developed and tested. Using the Stroop task and Wisconsin card sorting test for rigidity, research found that cognitive rigidity present in these two disorders is similar in the way that patients have difficulties alternating between modes of repetitive switching and single-tasks. In other words, they have problems adapting their cognitive mode. Research suggests that abnormal activity in the anterior cingulate cortex might be linked to cognitive rigidity.

Obsessive–compulsive disorder and major depressive disorder
OCD and major depressive disorder (MDD) often co-occur so it is a challenge to find neurobiological similarities and differences between the two but cognitive rigidity is a promising factor as it is typical for both disorders, can be assessed in patients and its neural underpinnings are not clear. Research using task switching revealed that OCD patients exhibit higher activation in areas such as the putamen, anterior cingulate and insula, whereas MDD patients show a lower engagement of areas such as the inferior parietal cortex and precuneus. Both patient groups showed minimal activation in the anterior prefrontal cortex during switching. The results of this study point to a certain form of cognitive rigidity in both OCD and MDD that might be linked to discrepancies in frontal-striatal brain dysfunction. Such discoveries may complement or support advanced identification of biological markers that depict co-occurring psychiatric illnesses more effectively.

Cognitive remediation therapy
Cognitive remediation therapy uses simple exercises to enhance executive functioning and reduce cognitive rigidity in patients suffering from anorexia nervosa to improve their general social functioning thanks to using real life examples and implications, which help patients gain a new perspective. It concentrates on the process of thinking rather than content.

Mindfulness based meditation
Mindfulness based meditation has been proved to reduce cognitive rigidity in both long-term meditators and non-meditators who underwent an 8-week program that teaches meditation and foundations of mindful approach to life. It teaches people to be open to new experiences and welcome change, targeting the issues associated with cognitive rigidity directly.