You or me?
If our grasp of ‘us and them’ goes wrong, we can have considerable problems in life
Most of us take for granted that we can tell the difference between an action we have generated ourselves and one forced on us by another. And most of our social interactions with other people are not consciously thought about. But if our brains are not adept at these activities, life can be very challenging.
People with schizophrenia, for example, show several distorted ways of thinking during psychotic episodes. A common symptom is to believe that one’s actions are being controlled by external forces. In brain scans, this is apparent in activity patterns characteristic of externally applied (rather than internally generated) movements. (An odd consequence of this is that, during a psychotic episode, people with schizophrenia can tickle themselves: they do not perceive the hand doing the tickling as their own.)
Similarly, people with schizophrenia will sometimes hear internal voices, urging them to do things. Brain imaging again shows brain activity corresponding to external sounds, not internal dialogue.
A third common symptom in people with schizophrenia is paranoia, a belief that people are following you or looking at you all the time. This appears to be an error in processing information from others – a casual glance ignored by most is interpreted as evidence of a deep interest and desire to cause harm.
It is possible that impaired pick-up of social cues also underpins other forms of behaviour disorder. People with antisocial personality disorder (psychopathy) seem less able to identify fearful expressions, so will be less able to tell that their behaviour is having a negative impact on people. Some symptoms of autism, too, seem to be linked to defective recognition of social cues (see ‘Mind the gap’).Lead image:
Stevie Taylor/Wellcome Images CC BY NC ND