Tuesday, November 15, 2011

Madness, Badness and Neuroimaging-based Responsibility Assessments (Part One)

Following on from my previous post looking at Nicole Vincent’s structured taxonomy of responsibility concepts (STRC), this post begins to take a look at another article by the same author. Subsequent posts will also look at this article. The article in question is:

Madness, Badness and Neuroimaging-Based Responsibility Assessments” in Freeman, M (ed) Law and Neuroscience: Current Legal Issues (vol. 13) (Oxford University Press, 2010)

As might be guessed from the title, the article deals with the role that advances in neuroimaging might play in responsibility assessments. Now, the phrase “responsibility assessments” is slightly ambiguous, but as becomes clear when one reads the article, Vincent is concerned with the kinds of assessment that take place within the criminal law.

In this post, I follow Vincent’s discussion by laying out the basic responsibility assessment process that is used in the criminal law, and then look at her suggested role for neuroimaging in this process. I close the post by identifying a problem with this suggested role (one that is also identified by Vincent), which is then taken up in the next post. You should note at the outset that some of the ideas in the STRC will show up in the discussion here. So you might like to take a look at the previous post on the STRC before reading this.

1. Responsibility Assessment in the Criminal Law
We hold people responsible for crimes. As students of criminal law will know, a crime is made up of two basic components or elements: the external element (traditionally called the “actus reus”); and the fault element (traditionally called the “mens rea”). These can be defined as follows:

External Element: This is the conduct, outcome or state of affairs that is deemed criminal. For example, a causal link between the actions of one person and the death of another is the external element of both the offence of murder and of manslaughter; damage to another person’s property is the external element of the offence of criminal damage; and non-consensual sexual intercourse is the external element of the offence of rape. Although this element of an offence was traditionally referred to as the “actus reus”, I think “external element” is better as criminal offences cover more than just “actions”.

Fault Element: This is the blameworthy mental state of the agent that accompanies the external element of the offence. It is usually the presence of the fault element that makes it right to hold the agent responsible for the external element. For example, intention to kill or cause grievous bodily harm is the fault element of murder; recklessness as to the outcome of one’s actions is the fault element of manslaughter, and so on. It’s worth noting that not all criminal offences have fault elements attached to them. There are such things as strict liability and no liability offences. For instance, where I come from, it is technically an offence to be found in a property with a television without a TV licence. This is true irrespective of whether one was knowingly, intentionally or recklessly without a TV licence. In other words, no excuses are tolerated (at least officially).

Because these two elements form part of most criminal offences, they provide a basic recipe or formula for criminal responsibility. It’s perhaps best to refer to this recipe as a “responsibility assessment process” just so the meaning is clear. The assessment process has, as Vincent notes, two stages to it: (i) determine whether or not the external element of the offence has taken place and can be linked to the actions of a particular agent; and (ii) determine whether or not the agent fulfills the criteria established by the fault element of the offence. (To those of you who are keeping tabs, this assessment process hearkens back to the outcome, causal, role and capacity concepts in the STRC.)

To give the example used by Vincent, suppose you come across the body of Smith in the forest. There is a gunshot wound to the head and the body has been hidden beneath a bush. The first thing you would do would be investigate whether Smith’s death by shooting could be linked back to the actions of another agent. This would be an investigation into the external element of the offence of either murder or manslaughter. To keep things simple, we’ll suppose that murder is the only relevant offence here.

Now suppose that your investigation is successful: you manage to link Smith’s death to the trigger pulling action of Jones. Then you confront the issue of blame: can Jones be blamed for Smith’s death? This, of course, would require an investigation into the fault element of the offence. There are two issues to consider here: was Jones’s conduct justifiable or was it excusable? This introduces us to two very important concepts in the criminal law:

Justification: We generally think that killing people is wrong. That is our default moral presumption. If Jones claims that his shooting Smith was justified, then he would be trying to rebut this default presumption. Pretty much the only way he can do this is if he can prove that he acted in self-defence. The best way to think about a justification is as a denial of wrongdoing.

Excuse: In contrast to a justification, an excuse is a denial of responsibility. If Jones claims that his shooting Smith should be excused, then he would be trying to show us that he does not match the criteria for responsibility. Typically, this will mean that he lacks some capacity that we expect of responsible agents or, alternatively, that a responsibility-relevant capacity that he normally has was impaired at the time of the offence.

Obviously, we would need to prove the absence of both of these possibilities before we could deem Jones responsible.

Vincent summarises the responsibility assessment process in the following schematic:

  • Mental capacity → can can’t → duties → culpability

Read from right to left, the schematic says the following: an agent is culpable when they violate their duties; their duties are dependent on what they can and can’t do; and what they can and can’t do is dependent on their mental capacities. If they lack some capacity that would be necessary for the performance of their duties, then they can be excused. Alternatively, if they are justified in what they do, then they have not — despite initial appearances — violated their duties.

2. A Suggested Role for Neuroimaging
Thus far we have been dealing with some pretty basic aspects of criminal law. Now we move on to the more interesting question: how might advances in neuroimaging affect the responsibility assessment process in the criminal law? Vincent suggests two possible roles.

First, it’s possible that neuroimaging could play a role in investigating the external element of the offence. The most obvious way in which this could happen is if one of the proposed lie-detecting or mind-reading tests that are based on neuroimaging technologies are proven to work. They could, in theory, help us to figure out what happened in the past and whether an agent’s actions were linked to (or constituted) a crime. As it happens, however, such technologies are subject to a number of limitations. I’ve actually written about this in past (see my personal webpage for more), and may do so again in the future. For now, we’ll these possibilities to the side.

Second, and more relevant here, neuroimaging could play a role in investigating the fault element of the offence. In particular, it could play a role in assessing whether or not the agent has the mental capacity we require for responsibility. The rationale behind this claim can be laid out in a simple formal argument. The argument refers to "Capacity X". This is intended to stand in for any responsibility relevant capacity. No specific capacity is mentioned because different theories of responsibility focus on different capacities.

  • (1) The mental capacity X (which is responsibility-relevant) is instantiated in or is some way constituted by a brain mechanism or set of brain mechanisms.
  • (2) Functional neuroimaging allows to see how sets of brain mechanisms are working.
  • (3) Therefore, functional neuroimaging will allow us to see how the mental capacity X is working.

The argument is not perfectly valid. I suspect an additional premise would be needed stipulating that if X is instantiated in or constituted by Y, then seeing how Y works is equivalent to seeing how X works. This might well be challengeable, or, at least, present significant hurdles for the use of brain scans in responsibility assessments. How so? Well, it could be that the mental code — i.e. the precise relationship between brain states and mental states — is both complex and convoluted. Consequently, reading how a particular mental capacity is working off of a scan showing how a particular brain mechanism is working could be quite tricky. Indeed, I suspect it is quite tricky.

This leads to another problem with the argument, namely: it presumes a very simple form of physicalism, one in which brain states, and only brain states, correlate with mental states. The problem is that one doesn’t need to be a dualist to deny this. Proponents of the extended mind thesis, for instance, would probably argue that mental states correlate with brain states and other physical states including states that are external to the body of the agent. If the extended mind thesis is true, then the argument will need to be revised.

But let’s not get bogged down in these problems here. Let’s assume, instead, that the argument is basically correct and that we can determine how a mental capacity is working from a brain scan. What then follows? In general, this kind of reasoning is attractive:

  • (4) The proper functioning of mental capacity X is a necessary condition for responsibility.
  • (5) Therefore, if mental capacity X is not functioning properly or is somehow impaired in a particular agent, then that agent cannot be held responsible for what they do.
  • (6) Therefore, if a brain scan reveals that brain mechanism Y (which constitutes or instantiates X) is not functioning properly in a particular, then that agent cannot be held responsible.

As I say, this kind of reasoning is attractive. It gives a very direct and important role to neuroimaging in responsibility assessments. To put it most simply, neuroimaging can be used to introduce evidence of incapacity. But as attractive as it may be, it throws up some problems. First, and most obviously, sometimes evidence of impairment works in the opposite way, i.e. it makes an agent seem more blameworthy, not less. This would be when the impairment suggests that the agent is morally evil, perhaps irredeemably so. Second, and similarly, it’s not clear that the relationship between agency-capacities and responsibility assessments is a straightforward as is being suggested here. In particular, it sometimes seems like a failure to have a properly functioning mental capacity can sometimes be blameworthy and that blame for particular actions can be traced back to the blame for having this improper mental capacity.

Vincent tries to resolve (or dissolve) the first of these problems in her article. We'll start looking at this in the next post.

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