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  4. AI Patent Law UK: Supreme Court to Decide on Neural Network Patentability in Emotional Perception Case

Overview

AI patent law is at a critical juncture. In November 2024, the UK Supreme Court granted Emotional Perception AI Limited permission to appeal the Court of Appeal decision in Comptroller-General of Patents, Designs and Trade Marks v Emotional Perception AI Limited [2024] EWCA Civ 825.

With the Supreme Court having now heard the case on 21–22 July 2025, and a judgment expected in the coming weeks, this blog provides a recap of the case so far and discusses the key arguments before the Supreme Court.

The Patent Application

Emotional Perception AI’s patent application relates to an artificial neural network (ANN).

Put simply, an ANN is similar to the brain – it is a group of connected artificial neurons that are capable of receiving inputs from a user outside of the system, processing those inputs based on instruction, and producing an output.

The ANN created by Emotional Perception AI is designed to recommend music files to a user based on “emotional similarity” with another music file – for example, the song’s mood, genre, tone and speed.

The Law

Section 1(2) of the Patents Act 1977 excludes from patentability a “program for a computer…as such” unless that program makes a “technical contribution”. This is known as the computer program exclusion.

Therefore, the key questions for the courts have been:

  1. Whether an ANN is a “program for a computer”; and
  2. If so, whether the ANN in question makes a “technical contribution”.

High Court Decision

After the IPO hearing officer rejected Emotional Perception AI’s patent application on the basis of the computer program exclusion, Emotional Perception AI appealed to the High Court of England and Wales.

The High Court held that the ANN was not a “program for a computer”, but even if it were, it made the requisite technical contribution for patentability. As such, the invention was not excluded from patentability pursuant to the computer program exclusion.

The decision was based on the following reasoning:

  • A computer program is something that “implements a series of instructions pre-ordained by a human”. However, once initial training is complete, an ANN “operates according to something that it has learned itself”, and therefore a trained ANN could not be considered a computer program.
  • The ANN’s recommendation of a music file, by providing that file as its output, constituted moving that file from one medium to another on the basis of an analysis, which is a technical effect. As such, it fell outside the computer program exclusion and could be patentable.

Court of Appeal Decision

The Court of Appeal disagreed and overruled the High Court’s judgment on the following bases:

  • A computer is a “machine which processes information”, and whether presented as hardware or software, an ANN is therefore a computer.
  • A computer program is a “set of instructions for a computer to do something”, regardless of whether the instructions are created by a human or computer. There is no justification at law for distinguishing between human and ANN-generated instructions. Therefore, the artificial neurons of an ANN fall within the definition of a “program for a computer”.
  • While the ANN may have applied technical criteria to create its output, this alone does not make the output itself a technical contribution. Instead, the ANN’s output (i.e., the media file recommendation) is based on qualities that are inherently subjective, rather than technical.

The Appeal to the Supreme Court

Leave to appeal to the Supreme Court was subsequently granted and a hearing took place on 21–22 July 2025.

The appeal focused on two main questions:

  1. Whether an ANN should be considered a computer program for the purposes of the Patents Act 1977; and
  2. If so, what is the correct approach to assessing the patentability of computer programs, particularly in the context of AI.

Key Arguments Before the Supreme Court

  • Alignment with European Patent Office (EPO) practice: Emotional Perception AI argued that the UK should align its approach with the EPO, which uses a “two-hurdle” approach (the “any hardware” test and the Comvik problem-solution approach) to assess patentability of computer-implemented inventions. This is in contrast to the UK’s current four-step Aerotel test.
  • Technical contribution: The parties debated whether the ANN’s output – recommendations based on emotional similarity – constitutes a technical contribution, or whether it is inherently subjective and therefore excluded from patentability.
  • Inventive step: There was discussion over whether the UK should adopt the EPO’s approach to inventive step (Comvik), or retain the UK’s Windsurfing/Pozzoli test, and how these frameworks interact with the statutory exclusions.

What’s Next?

It is anticipated that the Supreme Court’s decision will provide much-needed guidance on how to apply patent protections to AI – an issue of growing importance as AI technologies continue to develop rapidly.

The outcome will have significant implications for the future of AI-related patents in the UK, and for the alignment (or divergence) of UK and European patent law in this area.

We are likely to see a judgment around the autumn, so keep an eye out for our next update!

Need Advice on AI Patent Law in the UK?

Our London-based patent litigation lawyers have the expertise to deal with the legal issues that surround AI and patent law litigation.

If you have concerns about the application of patent protections to AI that are affecting your business, please contact Waterfront here and a member of our IP & Disputes team will be in touch.