Emotion, moral judgement, and Reason

Although classical AI approaches have usually neglected the emotional dimension, it is becoming a key part of many of the current artificial cognitive architectures. The neurobiological study of emotions during the last decades has offered new insight. The analysis of patients that have lost part of their brains, and the use of brain imaging techniques, give scientists many significant clues about how our emotional brain works.

In the book “Descartes’ Error: Emotion, Reason, and the Human Brain” by neurologist Antonio R. Damasio [1], the argument is made that emotion and reason are quite dependent upon one another. The famous case of Phineas Cage, whose frontal lobes were damaged in an accident, is explored in this book. Phineas P. Gage (1823-1860) suffered a brain injury at work when a tamping iron accidentally passed through his skull (see picture).

Gage’s case is said to be the first clinical proof of the role of the frontal lobe in personality and social interaction. Actually, after Gage suffered the accident, his friends said that he was no longer the same – he became a very unsociable person. The following is an excerpt from Harlow – Cage’s doctor (1968):

Gage was fitful, irreverent, indulging at times in the grossest profanity (which was not previously his custom), manifesting but little deference for his fellows, impatient of restraint or advice when it conflicts with his desires, at times pertinaciously obstinate, yet capricious and vacillating, devising many plans of future operations, which are no sooner arranged than they are abandoned in turn for others appearing more feasible. A child in his intellectual capacity and manifestations, he has the animal passions of a strong man. Previous to his injury, although untrained in the schools, he possessed a well-balanced mind, and was looked upon by those who knew him as a shrewd, smart businessman, very energetic and persistent in executing all his plans of operation. In this regard his mind was radically changed, so decidedly that his friends and acquaintances said he was ‘no longer Gage. [2]

Damasio proposed a theory called somatic marker hypothesis, which suggests a link between the fontal lobes, emotion, and decision making. Since Cage’s case, Antonio Damasio,  Marc Hauser and colleagues have studies six more cases with damage in the ventromedial prefrontal cortex (VMPC), one of the social motional nodes of the brain. They have concluded that this damage increases utilitarian moral judgements [3]. Here, the term utilitarian comes form utilitarism, and and refers to moral judgements or dilemmas where there is a conflict between aggregate welfare and highly emotionally aversive behaviors (for instance, having to sacrifice one person’s life to save a number of other lives).

According to Raymond J. Dolan,
Patients with medial prefrontal lesions often display irresponsible behavior, despite being intellectually unimpaired. But similar lesions occurring in early childhood can also prevent the acquisition of factual knowledge about accepted standards of moral behavior. [4]

[1] Antonio R. Damasio (1995) Descartes’ Error: Emotion, Reason, and the Human Brain
[2] Harlow, J.M. (1868). “Recovery from a Passage of an Iron Bar through the Head”. Publications of the Massachusetts Medical Society 2: 327-347.
[3] Michael Koenigs, Liane Young, Ralph Adolphs, Daniel Tranel, Fiery Cushman, Marc Hauser & Antonio Damasio. Nature 446, 908-911 (19 April 2007).
[4] Raymond J. Dolan. On the neurology of morals. Nature Neuroscience  2, 927 – 929 (1999).

Related Links:

Phineas Gage information page: http://www.deakin.edu.au/hmnbs/psychology/gagepage/index.php
Fact sheets on brain injury:  http://www.braininjury.org.au/portal/index.php

BEAR (Battlefield Extraction-Assist Robot)

BEAR (Battlefield Extraction-Assist Robot) is a prototype from Vecna Robotics [1] designed to find, pick up and rescue people in harm’s way. The BEAR can lift heavy loads (up to 135 Kg) and carry them long distance. It is intended to carry out rescue tasks where humans cannot access without risking additional human life.

BEAR is not an autonomous robot, but wireless control by a human operator. However, Vecna will implement autonomous beahviors in order to make it easier to control. Currently it is in a proof-of-concept development stage. The prototype has demosntrated picking up a fully-weighted human dummy.

Former prototypes were based on a two-wheels Segway automatic balance system (as can be seen in the first video below). However, current prototype (as shown in the picture and the second video below) is based on a set of tracks. Using this system, the robot can travel in a low profile ‘centaur’ posture and even kneeling.

The project is scheduled to finish in 5 years. Then this robot will be ready to be used in the field by the US Army Telemedicine and Advanced Technology Research Center [2].

The following videos show some of the former BEAR prototypes:

BEAR Robot in a park:

[1] Vecna Robotics Website.
[2] TATRC Website.

Multiple Draft Model

The Multiple Draft Model (MDM) introduced by Dennett (1991), uses the editorial review metaphor to describe the cognitive processes of consciousness.

In this domain, coalitions of unconscious processors suffer a reiterative edition and review process (producing a number of drafts). The last version obtained is the one that appears as a conscious content of the mind.

Dennett argues there is nothing such a central command center in the brain where some sort of director controls the self. On the contrary, all activity is developed by distributed sub-processes concurrently created in the brain. This could be seen as opposing Baars’ approach, where there is a central representation place for conscious contents (the spotlight in working memory). Actually, both accounts are materialistic, because they reject the Cartesian dualism (Baar’s spotlight does not correspond to a concrete point in the brain). However, materialism is more present in Dennetts’ account as there is not a conceptual central point. Additionally, Dennett explicitly rejects dualism, and state that it is the mere result of the ignorance and scientific incapability of some authors.

Staying away from the philosophical debate, and focusing on the functional standpoint, we can analyze how Dennett defines the conscious self as the owner of a point of view. Given that the brain has a limitation on the quantity of information that it can process at any given time, a conscious mind is an observer that collect a partial subset of the information coming from the environment. This information is not processed serially, in fact, the brain has a number of specialized modules that process this information in parallel. What Dennett adds to this view is that the information is continuously being revised and modified in order to adapt to the new incoming information. This explains our capacity of being simultaneously conscious of perceptions that take different time in being processed. (For instance, visual stimuli take more processing time than auditory ones).  What we consciously experience is the result of multiple interpretative processes. Many of the drafts that are built are discarded and disappear as time goes by. Only one version remains and takes part in the final narrative process, being stored in memory. These contents fixed in memory, which in turn affect consciousness, are also affected by the reviewing process. Given that a central reviewer that gives sense to the narration does not exist, there is no concrete instant in time when content becomes conscious.

Dennett argues that consciousness is executed in some sort of virtual machine modulated by cultural learning that runs on the brain parallel hardware. This virtual machine installs in the brain is a set of ‘mind habits’, which are not visible at a neuron-anatomic level. The successful deployment of such conscious machinery is possible thanks to a number of micro-dispositions produced due to brain plasticity.

To sum up, Dennetts’ proposed model implies that the conscious version of our thought is the winner of a continuous reviewer and change process. The factors that determine which will be the final official version at any given time can be diverse. For instance, during a rage episode, the coalitions of processors presenting more furious versions will be the winners. Anyhow, the brain will be always looking for an explanation that plausibly adapts to perception, but it doesn’t need to actually correspond to reality.