Monday, November 9, 2009

My good friend sometime back asked me how generalizable are psychological studies, when compared with the stupendous success of sciences like math and physics. I now have a reply somewhat near to answering that question.

Last October, an article appeared in the American Psychologist (the flagship publication of the American Psychological Association) by Jeffrey Arnett of Clark University (the only place in US graced by Freud). Arnett argued that research with subjects as Americans (comprising 5% of world population) cannot truly reflect the entire humanity and study of human nature. One of the issues was the sample taken to reflect the studied human trait such as aggressiveness, obedience and attention; and how well this sample could be generalized in the best possible way. A year after, the article attracted a string of responses. Of which I choose the one from Haeffel et al. The responders pick every Arnett argument apart.

Generalizability: Haeffel et al talk about the so-called college sophomore problem. It is called so as much of the American research recruits sophomores as subjects and so, the problem is that do such subjects reflect the entire American population in the first place (leave aside the world). But Haeffel et al brush aside this problem as “consistency of research findings across contexts and samples should not be surprising given that all humans, whether they live in America or a developing country, share a common genome, brain organization, and capacity for cognition, perception, and emotion.” Universals do exist. An example is the research of the brilliant Paul Ekman who showed facial expressions are universal. Everyone looks angry the same away from Nagpur to Norway. Ekman discovered seven universally expressed emotions: anger, fear, disgust, surprise, sadness, happiness and contempt. For him, love is not an emotion as emotions can come and go in a matter of seconds, but love lasts.

Move away form basic processes: These processes are things like cognition, perception and learning. And Arnett thinks that psychological research has to move away from these processes and focus on culture and diversity. This means we should study specific real-time problems such as religious fundamentalism, war and HIV pandemic rather than hark back upon the basic thinking and learning processes. Haeffel et al counter that this is a “fundamental misunderstanding” about basic research, as development in information processing led to the formulation of the cognitive behavioral therapy (CBT) and in turn, to treat depression, anxiety, etc. Arnett makes a valid point that the roots of the therapy lie not in information processing research but in the work of Albert Ellis and Aaron Beck (the CBT pioneers) and even goes back to Greek thought.

Maybe, a better example is treating post traumatic stress disorder (PTSD, with war veterans being the worst affected) by doing basic research in memory. PTSD is an emotional illness arising due to a catastrophic event that may threaten life or is emotionally numbing. Every survivor of a gruesome accident, for example, need not have PTSD but in some, this is the case. In 1960s, a key neuroscience tenet was that memories take time to become permanent (through a process called consolidation); and such memories cannot be erased. For the next 35 years, hardly was any research done to disprove this.

Then Alan Brunet of McGill University in Canada went on to show something remarkable. A survivor was asked to recall the accident, she relived several times in her mind. But before that she took a low dose of a drug called propranolol that inhibits amygdala, the almond-shaped part of the brain dubbed its emotional center. With the drug consumed, the memory of the accident wasn’t gone but the negative emotions of it like the terror and trauma were stripped away. This molecular manipulation of the brain’s systems meant memories could be altered. The Discover Magazine puts this beautifully:

Memory formation requires an elaborate chemical choreography of more than a hundred proteins, but the upshot is that sensory information, coded as electrical pulses, zips through neural networks of the brain. The impulses cause glutamate (one of the brain’s main neurotransmitters) to pop out of one nerve cell and travel across the synapse to activate the next by binding to its receptors, chemically active signaling stations on the cell surface. Ultimately the electrical and chemical signals reach the centers of memory, the almond-size amyg¬dala and the banana-shaped hippocampus, adjacent structures buried on either side of the brain.

Neuroscientists believe that memory forms when neurons in these key brain structures are simultaneously activated by glutamate and an electrical pulse, a result of everyday sensory experience. The experience triggers a biochemical riot, causing a specialized glutamate receptor, called NMDA, to spring open and allow calcium ions to flood the cells. The ions stimulate dozens of enzymes that reshape the cells by opening up additional receptors and by prompting the formation of more synapses and new protrusions that contain still more receptors and synapses. In aggregate, these changes make neurons more sensitive to each other and put the anatomical scaffold of a memory in place.

Enacting all these changes takes time, and for up to a few hours the memory is like wet concrete—solidifying but not quite set, still open to interference. Once the process is over, though, the memory is said to be “consolidated.” In the textbook description, neuroscientists talk of memory the way geoscientists describe mountains—built through a dynamic process, but once established almost impossible to reshape quickly except by extraordinary means.

…Instead of being a perfect movie of the past, psychologists found, memory is more like a shifting collage, a narrative spun out of scraps and constructed anew whenever recollection takes place.

So the point is that basic processes like memory should be studied that have far-reaching effects (which may not be immediately apparent). One shouldn’t forget that the brain is a well-integrated and the most complex protoplasm in the universe.

Haeffel et al conclude that:

Focusing on cultural context rather than basic processes is not going to advance American psychology, or psychology in general. Neither are having students travel abroad or take anthropology classes (as recommended by Arnett), in and of themselves. Rather, science will advance by developing and testing theories. We believe that psychological science can benefit most by using differences in culture and context to develop and test novel hypotheses about basic human processes.

A little away from this viewpoint, Arnett concludes that:

Psychology needs to get over its “physics envy” and adapt its methods and theoretical approaches to its uniquely human topic, in all its cultural complexity and diversity, rather than endlessly and fruitlessly aping the natural sciences.

Arnett wants “the structured interview and the ethnography are no less legitimate as tools of the scientific method than are the laboratory or the questionnaire.”

In all this, Arnett has raised an important debate: how human is psychology in its attempts to understand humanity? And it is this human focus that sets psychology aside from other disciplines.

No comments: