Cognitive Explanations for Schizophrenia

Cognitive Explanations of Schizophrenia

Cognitive explanations for schizophrenia explore how dysfunctional thought processes enable the development of schizophrenia, including theories on abnormal thought processes, meta-representation, and central control. According to the cognitive explanation, dysfunctional thought processing leads to symptoms of schizophrenia by facilitating the development of delusions and memory and perception issues.

Dysfunctional Thought Processing

Dysfunctional thought processing focuses primarily on the faults in our thought processes. In schizophrenia, it is suggested dysfunctional thought processing leads to the development of the disorder.

Firth (1992) highlighted how cognitive issues are linked to schizophrenia by discussing how those with schizophrenia show an impairment with Theory of Mind (ToM), known as the cognitive neuropsychological model. Firth (1992) identified two key aspects of dysfunctional thought-processing issues:

1. Metarepresentation (a disorder of understanding the self and others)
2. Central Control (a disorder of controlling actions)

Firth (1979) also suggested that schizophrenia was due to a faulty attention system, known as the attention-deficit theory. Preconscious thoughts (thoughts occurring without active awareness or attention, which are automatic responses) filter the world, so we are not bombarded with information. If filtering does not occur, the mind can be overloaded with information.

According to Firth, this is responsible for most of the positive symptoms associated with schizophrenia and psychosis.

• Beech (1989) provided support for Firth's (1979) theory of selective attention issues by examining the concept through negative priming. They found that there is an impaired ability to inhibit distracting information in schizophrenic people.

• Hemsley (1993) argued that there is a fundamental breakdown between memory and perception in those with schizophrenia, and schizophrenic patients struggle to activate schemas appropriately.

Matussek (1952; as cited in Hemsley, 2005) highlighted how, in a patient with schizophrenia, there was a:

Fig. 2 - Firth (1992) identified metarepresentation and central control as key cognitive aspects of schizophrenia.

What are Attentional Biases and Deficits?

Bentall (1994) states that abnormal attention in those with persecutory delusions in schizophrenia (an inability to recognise what is real) is given to threatening stimuli. They are biased towards these stimuli due to a lack of self-monitoring. In one sense, they blame their delusions and hallucinations on the outside world or external sources.

Deficits exist in patients having trouble processing different types of information and can range from moderate to severe. This can affect social situations, as patients misunderstand or completely miss social cues and emotional prompts. Deficits can account for reduced levels of emotional expression and confusing speech patterns, as patients have consequently avoided and struggled with social situations.

Dysfunctional Thought Processing: Metareprersentation and Central Control

Firth (1992) highlighted two key aspects to dysfunctional thought processing in schizophrenia and linked them to the symptoms. These are:

1. Meta-representation
2. Central Control

What is Metarepresentation?

Metarepresentation is about how we understand that we are responsible for our thoughts, behaviours, and actions. By paying attention to our thought processes and how we got from thought A to B to C and so on, we can justify our decisions! We can also tell that these thoughts are our own.

Schizophrenic patients struggle to differentiate between external sources of information, such as speech, and their own thoughts.

Fig. 3 - Metarepresentation is our ability to understand our thoughts, behaviours, and actions.

• Being able to reflect on thought processes and feelings allows for an insight into personal behaviours, intentions and, ultimately, a person’s goals for future decisions - it is what gives a person self-awareness (similar to ToM). It also allows you to interpret the actions of others and understand their intentions and goals.

• Faults in this system result in delusions of control. If someone is not able to follow their train of thought or identify their thoughts as their own due to external inputs interfering (such as speech from others), and there’s no logical consistency or ability to say outright, ‘I did this because I thought of this’, it can feel like someone else is controlling your thoughts and actions (thought insertion).

• After all, if this process is faulty, how can you say that a particular action was your own when you don’t truly know what led to this action?

As a result, this can manifest in hallucinations and delusions in patients with schizophrenia. In meta-representation, positive symptoms (like hearing voices) make it hard for a person with schizophrenia to distinguish their thoughts from the voices they hear.

Evaluation of Metarepresentation

Meta-representation has its own strengths and weaknesses:

• In Firth’s (1992) study, 30 schizophrenic patients had PET scans. This is where radioactive ‘tracing’ fluid is injected into the body, which shows where highly metabolic and biochemical areas are. This means there’s a high activity level in those brain portions. The scans in this study revealed that there was reduced blood flow to the frontal cortex in the brain.

• This, in turn, is associated with negative symptoms such as avolition and the inability to suppress automatic thoughts and behaviours.

• There was also increased activity in the temporal lobe, which is responsible for retrieving memories. For patients with reality distortion, this suggests a biological difference in schizophrenic patients and the way they process thoughts, supporting the theory.

• Beech (1989) also supported Firth's theories (1979) on selective attention issues.

What is Central Control?

Central Control is the ability to suppress or override automatic thoughts, actions and speech in response to stimuli. Self-control can be faulty in patients with schizophrenia.

Fig. 4 - Central control is the ability to suppress and override automatic thoughts.

• Patients with schizophrenia, who have difficulty resisting such urges, press the button. But they are unable to explain why they chose to do it fully.

• This can result in delusions. When an individual with schizophrenia cannot explain why they did something or identify where the thought came from in the thought process, it can create feelings of paranoia. Sometimes the line of thought is jumbled, or sections are missing completely. They then question reality and themselves and ultimately cannot find an internal, rational source for their decision-making.

• Speech can also be affected. Conversation topics will frequently shift and change. It’s hard to resist speaking out loud when such thoughts would usually be filtered out or dismissed. Topics can trigger thoughts that are hard to suppress and can result in disorganised speech.

Evaluation of Central Control

Central control has its own strengths and weaknesses.

• Stirling (2006) conducted a study where he used the Stroop Test on 30 and 18 control patients, concluding that thought disorders are linked to semantic processing impairments.

• The Stroop Test is where patients are given the name of a colour, for instance, blue, but the actual word will be in different coloured ink. So, blue would be written in yellow ink. Patients are asked to say the colour of the ink, NOT the actual written word.

• Central control would help a person resist the urge to shout the written word.

• In schizophrenic patients, it took twice as long to name the ink colour as the controls, suggesting issues with thought processing and, ultimately, a dysfunction with central control.

• However, this theory has problems with reductionism. It tends to ignore other factors and explain the complex disorder of schizophrenia through the lens of dysfunctional thought processing.

• It helps explain positive symptoms (hallucinations) but does not identify exactly where they come from.