Cognitive Approach
- There is evidence that people diagnosed with schizophrenia have difficulty with processing what
they perceive, they may also suffer from attention deficits.
- Cognitive deficits have been suggested as possible explanations for a range of behaviours
associated with schizophrenia, including reduced levels of emotional expression, disorganised
speech and delusions.
Explaining Hallucinations
- Anthony Morrison proposed that certain triggers, such as sleep deprivation, can cause some
individuals to have maladaptive auditory hallucinations,
- Individuals inappropriately appraise these voices as belonging to figures like the devil.
- This elicits negative behaviours such as self-harm or withdrawal, leading to emotions like shame
and sadness. These emotions reinforce the messages from the voices and causes a vicious cycle.
- Frith (1992) suggested that schizophrenics don’t feel in control of their own inner voice,
attributing it to the outside world and misinterpreting the messages it gives.
- Frith speculated that these cognitive deficits were linked to an irregularity in the neuronal
pathways running between the septo-hippocampal system and prefrontal cortex.
- McGuire et al (1996) found that schizophrenics have reduced activity in parts of the brain
involved in monitoring inner speech.
- Other research has also found through PET scans reduced activity in the frontal lobe of
schizophrenics.
Explaining Negative Symptoms
- There has been less cognitive research into the negative symptoms of schizophrenia.
- Beck (2008) applied the cognitive triad to certain negative symptoms, proposing that individuals
approve dysfunctional beliefs about their performance and their ability to experience pleasure.
- Mental filters only allow in negative messages and deficits in information processing bolster the
pessimistic view.
- This leads to negative symptoms such as avolition and anhedonia.
Lack of preconscious filters
- Frith (1979) proposed that the core positive symptoms of schizophrenia could be explained by
difficulties in inhibiting preconscious (thoughts without awareness) content. This is known as his
‘attention deficit theory’
- Normally, our senses receive huge amounts of information from the world around us and this
reaches our awareness so we can interpret it.
- The most sensical interpretation of the information is then allowed into our consciousness so we
can comprehend the information.
- Frith proposed that the filters which inhibit certain information from entering the consciousness
are defective in schizophrenics. This leads to schizophrenics to ‘become aware of ambiguous and
multiple interpretations of events and find it difficult to select and carry through an
appropriate course of action.’
- Since we are constantly exposed to so many environmental factors, it is no surprise that not being
able to ignore any of them could lead to being overwhelmed.
- Bentall (1994): Schizophrenics have an attention bias towards stimuli of a threatening or
emotional nature, and are also more likely to perceive a stimuli as threatening when it isn’t
which could lead to delusions of persecution.
- David Hemsley (1993, 2005): schizophrenia involves a breakdown in the relationship between
memory and perception, two keep IMP’s. As a result, there is a disconnect between schemas and
what is actually perceived.
- This can lead to sensory overload as it is difficult to know what to attend to and what to ignore
which may lead to disorganised thinking and behaviour.