Exploring Brain Function in Psychology & Neuroscience

1. Psychology and neuroscience Dr. Andrew YoungBehavioural Neuroscience Groupamjy1@le.ac.uk PS1009 Applied Psychology

2. Psychology and brain function Integration Decision Transmission Neuronal connectivity Neurones Chemicals (Neurotransmitters) Electrical activity • As psychologists we study the interaction between an organism and its environment • Perceiving the environment (sensory perception) • Behavioural responses The Brain

3. Brain function and behaviour • Post-mortem study of brain showed: • single lesion towards back of left frontal lobe • first evidence for highly localised control of function in the cortex • Paul Broca (c1860) • Studied a patient called ‘Leborgne’ • intelligent and capable of comprehending spoken and written language • but unable to speak more than a very few meaningless syllables for 21 years • capable of communication using motor gestures

4. Types of measurement • Post-mortem studies • Provides anatomical information • Of limited value for functional studies • Living neurones in isolation (in vitro - e.g. cultures, slices) • Show how living neurones can function • But give limited information on behaviour • Studies intact brains • Effects of brain injury on behaviour • Effects of drugs with known pharmacology on behaviour • Monitoring brain activity during behaviour • Underpinned by post-mortem and in vitro studies

5. Study of normal brain function * * * • Neuronal systems involved – e.g. hippocampus • Electrical process involved – e.g. LTP • Neurotransmitters involved – e.g. glutamate * * (* see PS1003 lectures) • Perception – vision, sight, smell, taste • Movement • Language • Learning and memory • Sleep • Pain and analgesia • Mood • Personality • ….. many more

6. Study of abnormal function • Studying neuronal processes and/or neurotransmitters involved in • Perceptual disorders • Motor disorders • Schizophrenia • Depression • Anxiety • Parkinson’s disease • Ischaemia (stroke) • Epilepsy • Addiction • ….. many others

7. Symptoms of psychosis • Abnormal ideas : • delusions (mood, persecution, grandiose, hypochondriacal) • Abnormal perceptions : • hallucinations (mainly auditory) • Formal thought disorder : • derailment, loss of goal, neologisms, poverty of speech content • Motor, volition and behavioural disorder : • catatonia, abnormal posture, avolition, mutism, • Emotional disorders : • affective flattening, emotional withdrawal, anhedonia. Difficult to measure objectively

8. Can psychology help us understand schizophrenia? • Understanding biological basis of psychological function • - relationship with dysfunction in psychiatric disease • effects of brain injury on behaviour • effects of drugs on behaviour • pharmacology of drugs with therapeutic effects • studies with tasks which rely certain brain areas • brain imaging studies, especially function in these tasks • use of animal models of psychological function

9. Effects of brain injury on behaviour • Temporal lobe dysfunction (e.g. temporal lobe epilepsy) • Can lead to some symptomssimilar to positive symptomsof schizophrenia. • Frontal lobe damage (e.g.frontal lobectomy) • Leads to symptoms similarto negative symptoms ofschizophrenia.

10. Effects of drugs on behaviour Several drugs known to cause symptoms similar to schizophrenia: • Amphetamine – causes hallucinations and delusions very similar to positive symptoms of schizophrenia • Are positive symptoms associated with increased dopamine? • LSD – causes hallucinations which are similar the positive symptoms of schizophrenia • Are positive symptoms associated with increased serotonin?

11. Pharmacology of drugs with therapeutic effect • Classical (‘typical’) antipsychotic drugs • Antagonists at dopamine receptors • Newer (‘atypical’) antipsychotic drugs • Antagonists at both dopamine and serotonin receptors Dopamine and serotonin over-activity both implicated in schizophrenia.

12. Studies using tasks relying on certain brain areas • Positively symptomatic schizophrenics are deficient in tasks requiring temporal lobe function • e.g. selective attention – latent inhibition (learning to ignore irrelevant stimuli) • Schizophrenics are deficient in tasks requiring frontal lobe function • e.g. Wisconsin card sort, Tower of Hanoi • First degree relatives of schizophrenics are also deficient in frontal lobe tasks.

13. Brain imaging studies Z-coordinate of slice -2 4 9 Right Left Young AMJ et al., 2005 • Functional magnetic resonance imaging (fMRI) studies have looked at brain areas activated during these tasks: • e.g. Latent inhibition • How does this differ in schizophrenic patients?

14. Animal models of psychological function Schizophrenia SALINE Poor Good Learning LI AMPH +HAL AMPH NON-PREEXPOSED PREEXPOSED Latent inhibition in animals – relationship with schizophrenia Latent inhibition provides a model for studying the neural basis of schizophrenia

15. Information processing deficits in schizophrenia Kraepelin (1913) "Schizophrenic patients are unable to exclude irrelevant sensory information from their awareness" McGhie & Chapman (1961) "I can't shut things out" Pateint A : "I let all the sounds come in that are there" Patient B : "I'm attending to everything at once, so I don't Patient C : really attend to anything" These may be indicative of deficits in sensory gating (e.g. selective attention).

16. Psychology and neuroscience • Understanding the neural and neurochemical basis of psychological function in the normal brain • Perception • Intrinsic processing • Motor output • ‘Behaviour’ • Studying the neural and neurochemical basis of behaviour gives us insights into dysfunctions underlying psychiatric disease.