28 - Stream of Thought

Stream of Thought:

© SPMM Course space, demonstrating graphical connections between people and qualities in the patient’s personal world. 3. Mortimer considered FTD to be a result of impaired semantic memory – so associations between words and qualities are lost. 4. Words carry a semantic halo – e.g. the word ‘London’ is linked, through symbolic meaning to words like ‘tube’ and also ‘Britain’, ‘England’, etc. Imagine that these words are cross-wired in the brain. So whenever the word London is stimulated, the closely cross-wired words also become available readily for the thought process to proceed uninterrupted. This activation is called direct semantic priming. In Indirect semantic priming, London activates tube; tube activates light (as in tube light) or pipes, etc. This indirect priming is usually minimal, preventing inappropriate deviation in determining the tendency of thought flow. In schizophrenia, it is proposed that direct priming is impaired but indirect one is activated more, to explain FTD. 5. Theory of mind refers to the ability to understand that other individuals have mental processes similar to self, leading to appropriate behaviour and conversation e.g. taking turns while conversing (as others also think and so want to speak). This is deficient in the development of autistic children and can become acutely deficient (but develops normally) in schizophrenia during psychotic episodes. This can explain some pragmatic errors in FTD. 6. Dysexecutive problems are increasingly proposed as the basis of FTD. Frontal lobe plays significantly in formation of the human language ad so the loss of executive functions can result in poor planning, error monitoring and correction of speech production.

Stream of Thought: The term pressure of speech refers to the phenomenon of having excessive thoughts in mind accompanied by rapid voluminous speech, often disjointed and non-pragmatic. This is seen in mania. Crowding of thought occurs in schizophrenia. Here the patient describes his thoughts as being passively concentrated and compressed in his head. The associations are experienced as being excessive in amount, too fast, inexplicable and outside the person's control. Experientially, this is different from the manic flight of ideas. Retardation of thinking: Seen in depression. Train of thought is slowed down, though goal-directed, it is characterised by little initiative or planning, the long latency of response, increased pause times when speech is initiated and during speech. In both the above the mood state of the patient dictates the flow of thoughts. Perseveration: This could be considered under a stream of thought though traditionally, it is considered pathognomonic of organic brain disease; it is also discussed with disorders of motor action. The thought process tends to persist beyond a point at which they are relevant. It presents itself as repeatedly same answer or motor act even if the stimulus that elicits the response has changed and demands a different answer or motor act. Perseveration also occurs if there is clouded consciousness.